Applicator instruments having drive systems with flexible members for dispensing surgical fasteners

ABSTRACT

An applicator instrument for dispensing surgical fasteners includes an elongated shaft, a housing connected with the elongated shaft, a trigger, a gear train, and a firing system disposed in the housing. The trigger is squeezed for commencing a firing cycle. The firing system includes a storage reel, a spool connected to the storage reel, a drive wheel located distal to the storage reel and the spool, a constant torque spring having a proximal end connected to the spool and a distal end connected to the drive wheel, and a flexible member in contact with the drive wheel. The flexible member has a proximal end connected to the storage reel and a length configured to be driven by the drive wheel toward the distal end of the elongated shaft. During an energy storing stage, the gear train is coupled with the storage reel for rotating the storage reel in a counterclockwise direction, which, in turn, retracts and winds the flexible member onto the storage reel, which rotates the drive wheel in a counterclockwise direction and winds the constant torque spring from the spool onto the drive wheel for storing energy in the constant torque spring.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present patent application claims benefit of U.S. ProvisionalApplication Ser. No. 62/431,355, filed Dec. 7, 2016, and is related toU.S. patent application Ser. No. 15/372,241, filed Dec. 7, 2016,entitled “SURGICAL FASTENERS FOR MESH AND TISSUE FIXATION” (AttorneyDocket No. ETH5878USNP), the disclosures of which are herebyincorporated by reference herein.

BACKGROUND OF THE INVENTION Field of the Invention

The present patent application is generally related to medical devices,and is more specifically related to medical devices that dispensesurgical fasteners for securing prosthetic devices to tissue.

Description of the Related Art

A hernia is a condition where a small loop of bowel or intestineprotrudes through a weak place or defect within the abdominal musclewall or groin of a patient. This condition commonly occurs in humans,particularly males. Hernias of this type may result from a congenitaldefect whereby the patient is born predisposed with this condition,prior abdominal surgery, or may be caused by straining or lifting heavyobjects. Heavy lifting may be known to create a large amount of stressupon the abdominal wall and can cause a rupture or tearing at a weakpoint of the abdominal muscle to create the defect or opening. In anycase, the patient may be left with an unsightly bulge of intestinaltissue protruding through the defect, which may result in pain, reducedlifting abilities, and in some cases, impaction of the bowel, orpossibly other complications if the flow of blood is cut off to theprotruding tissue.

A common solution to the above-described problem may be surgery. Duringa surgical procedure, the defect is accessed and carefully examined,either through an open incision or endoscopically through an access portsuch as a trocar. In either case, careful examination is required due tothe network of vessels and nerves which exist in the area of a typicaldefect, which requires a surgeon to conduct a hernia repair with greatskill and caution. Within this area can be found vascular structuressuch as gastric vessels, the external iliac vessels, and the inferiorepigastric vessels, as well as reproductive vessels such as the vasdeferens extending through the inguinal floor.

Once the surgeon is familiar with the anatomy of a patient, the surgeoncarefully places the viscera back into the patient's abdomen through thedefect. Repairing the defect can involve closure of the defect withsutures or fasteners but generally involves placing a surgicalprosthetic such as a mesh patch over the defect, and attaching the meshpatch to the abdominal wall or inguinal floor with conventional sutureor with surgical fasteners. The mesh patch acts as a barrier andprevents expulsion of bowel through the defect. Suturing of the meshpatch to the inguinal floor can be well suited to open procedures butcan be much more difficult and time consuming with endoscopicprocedures. With the adoption of endoscopic surgery, endoscopic surgicalinstruments that apply surgical fasteners can be used. However, thetissue of the inguinal floor may offer special challenges to the surgeonwhen a needle or fastener is used to penetrate structures such asCooper's ligament.

At present, there are a variety of surgical instruments and fastenersavailable for the surgeon to use in an endoscopic or open procedure toattach the mesh patch to the abdominal wall or inguinal floor. One ofthe earliest types of endoscopic surgical instruments used is a surgicalstapler. A plurality or stack of these unformed staples may be generallycontained within a stapling cartridge in a serial fashion, and may besequentially advanced or fed within the instrument by a springmechanism. A secondary valving or feeding mechanism may be employed toseparate the distal-most staple from the stack, to hold the remainder ofthe spring loaded stack, and may be used to feed the distal-most staplesinto the staple forming mechanism. Feeding mechanisms of this type arefound in U.S. Pat. No. 5,470,010 to Rothfuss et al., and in U.S. Pat.No. 5,582,616, also to Rothfuss et al.

Another hernia mesh attachment instrument uses a helical wire fastenerthat resembles a small section of spring. Multiple helical wirefasteners may be stored serially within the 5 mm shaft, and may becorkscrewed or rotated into tissue. A load spring may be used to bias orfeed the plurality of helical fasteners distally within the shaft. Aprotrusion extends into the shaft to possibly prevent the ejection ofthe stack of fasteners by the load spring and may permit passage of arotating fastener. Instruments and fasteners of these types are found inU.S. Pat. No. 5,582,616 to Bolduc et al., U.S. Pat. No. 5,810,882 toBolduc et al., and in U.S. Pat. No. 5,830,221 to Stein et al.

Whereas the above surgical instruments may be used for hernia fasteningapplications, they use a spring mechanism to feed a plurality offasteners through the surgical instrument. Spring mechanisms typicallyuse a long soft coil spring to push a stack of fasteners through a guideor track within the shaft of the surgical instrument. These types offeeding mechanisms may be generally simple and reliable, but may requirean additional secondary valving mechanism or protrusion to separate andfeed one fastener from the stack.

Other surgical fasteners may be used for hernia mesh attachment bututilize either a reloadable single shot instrument or a rotary magazinethat holds a small number of fasteners. These types of surgicalfastening instruments can be found in U.S. Pat. No. 5,203,864 and U.S.Pat. No. 5,290,297, both to Edward Phillips. These instruments have notgained acceptance by the surgical community, possibly due to theirsingle shot capabilities and the large size of the rotary magazine,which can restrict such an instrument to an open procedure.

Whereas all the above surgical instruments may be used for herniafastening applications, they either use a spring mechanism to feed theplurality of fasteners through the surgical instrument, or a rotarymagazine in lieu of a feeding mechanism. Other types of surgicalfasteners may be available, such as surgical clips, and they can utilizefeeding mechanisms that do not require the use of a spring to feed theclips distally. A reciprocating feeding mechanism is described in U.S.Pat. Nos. 5,601,573; 5,833,700; and 5,921,997 to Fogelberg et al. TheFogelberg et al. references teach a clip applier with a feedingmechanism that utilizes a reciprocating feed bar to feed a serial stackof clips. A feeder shoe may operably engage with and move with thedistally moving feed bar and may slidingly engage with the proximallymoving feed bar. Thus, the feeder shoe may index or push the stack ofclips distally with the distally moving feed bar and remains stationaryrelative to the proximally moving feed bar. A valving mechanism may bealso required to separate the distal-most clip from the stack and tohold the stack stationary as the distal-most clip may be applied onto avessel. Whereas the Fogelberg et al. references teach a reciprocatingfeeding mechanism with a single reciprocating member, they do not teachthe use of the clip applier in the attachment of hernia mesh, nor dothey teach the individual driving or feeding of each clip by a movingmember.

U.S. Pat. No. 3,740,994 to DeCarlo Jr. discloses a reciprocating feedingmechanism that indexes a plurality of staples or clips, and readies themfor discharge by reciprocating one of a pair of opposing leaf springassemblies. The staples reside serially within a guide rail with a fixedleaf spring assembly extending into the plane of the guide rail. Areciprocating leaf spring assembly may extend inwardly towards the fixedleaf spring assembly. As the reciprocating leaf spring assembly movesdistally, each of individual leaf springs of the assembly may engage astaple and move it distally. The distally moving staples deflect thelocal individual leaf springs of the fixed leaf spring assembly, and thedeflected leaf springs may return to the un-deflected position afterpassage of the staple. As the moving leaf spring assembly movesproximally, the leaf springs of the fixed leaf spring assembly hold thestaples stationary and prevent proximal movement thereof. A secondaryguide rail and valving mechanism may be provided to separate a singlestaple from the stack for forming and can hold the stack of staplesstationary as the single clip is formed.

Additionally, similar feeding mechanisms are disclosed in U.S. Pat. No.4,478,220 to DiGiovanni et al. and U.S. Pat. No. 4,471,780 to Menges etal. Both of these related patents teach a reciprocating feedingmechanism that uses one fixed member and one reciprocating member tofeed or index a plurality of clips distally. Angled flexible fingers maybe hingedly attached to the reciprocating member and operatively engagethe clips when moving distally, and slidingly engage with the clips whenmoving proximally. The angled flexible fingers within the fixed memberdeflect out of the way when the clips move distally and spring up tostop proximal movement of the clip after the clip has passed. Asecondary valving mechanism is also disclosed.

Commonly assigned U.S. Pat. No. 7,485,124, the disclosure of which ishereby incorporated by reference herein, teaches a device for deliveringa plurality of individual surgical fasteners. In one embodiment, thedelivery device includes a drive mechanism having distal and proximalends. The drive mechanism has a moving member and a fixed opposingmember, whereby the moving member is moveable proximally and distallywith respect to the delivery device. The moving member has a sharpeneddistal end for piercing tissue. The device includes at least onesurgical fastener located between the first and the second members. Eachof the at least one surgical fasteners has a proximal end and a distalend. The device also has an actuator having at least two sequentialpositions. A first position for moving the moving member distally andpiercing tissue, and a second position for moving the moving memberproximally, thereby deploying the distal end of the fastener.

Tacks for fixing meshes used laparoscopically have generally been madeof metal, such as stainless steel, nitinol, or titanium. The metal tackswere necessary to provide for sufficient holding strength, penetrationof various prosthetic meshes, and for ease of manufacture. Untilrecently, there were no absorbable tacks available on the market, andsurgeons could only use absorbable sutures in order to provide afixation means that did not permanently stay in the body. However, usingsutures is exceedingly difficult for laparoscopic procedure, and so theyare generally not used unless the repair is done in an open fashion.With surgical trends leading to more minimally invasive techniques withminimum foreign body accumulation, an absorbable tack with minimumprofile that can be applied laparoscopically is needed.

Commonly assigned U.S. Pat. No. 8,920,439, the disclosure of which ishereby incorporated by reference herein, discloses an applicatorinstrument for dispensing surgical fasteners having an elongated shaftwith a proximal shaft section and a distal shaft section. The applicatorinstrument has an articulation controller coupled with the distal shaftsection for selectively changing the angle between the distal shaftsection and the proximal shaft section. The articulation controller hasat least one flexible linkage extending through the shaft and has aproximal end connected with an actuator and a distal end connected withthe distal shaft section. The actuator is mounted on a housing forsliding between proximal and distal ends of the housing for moving theat least one flexible linkage in proximal and distal directions.Surgical fasteners are disposed within elongated shaft for beingdispensed one at a time from the distal end of the elongated shaft.

In spite of the above advances, intra-operative conditions duringlaparoscopic surgery remain challenging for the surgeon. There is a needfor flexibility, both with respect to surgeon ergonomics and fasteneroptions. Regarding ergonomics, there remains a need for applicatorinstruments for dispensing surgical fasteners that have improvedergonomics, that enable ipsillateral (same side) mesh tensioning, andthat provide maneuverability both inside and outside of a body cavity.There also remains a need for applicator instruments for dispensingsurgical fasteners that have an optimal distal shaft strength when theshaft is articulated, and that provide pre-defined articulation anglesfor simplifying the device complexity and the user experience. Therealso remains a need for applicator instruments that have improvedergonomics for accommodating a diverse range of trocar placements,including both midline and lateral trocar placements. In addition, thereis a need for tailored fastener solutions to accommodate the diverseneeds of patients. Moreover, related to this need, there is a need toreduce procedural costs and increase flexibility during surgicalprocedures.

SUMMARY OF THE INVENTION

In one embodiment, an applicator instrument for dispensing surgicalfasteners preferably includes an elongated shaft having a proximal endand a distal end, a housing connected with the proximal end of theelongated shaft, a trigger for activating a firing cycle, a gear traincoupled with the trigger, whereby the trigger is squeezable for movingthe gear train for commencing a firing cycle, and a firing systemdisposed in the housing. In one embodiment, the firing system is coupledwith the gear train during an energy storing stage of the firing cycleand decoupled from at least one gear of the gear train during an energyreleasing stage of the firing cycle. In one embodiment, the applicatorinstrument desirably has a handle connected to the housing and a triggercoupled with the handle. The handle and the trigger may rotate togetherand relative to the housing for moving the handle and the triggerbetween a pistol configuration and an in-line configuration.

In one embodiment, the firing system includes a storage reel, a spoolconnected to the storage reel for rotating simultaneously with thestorage reel, a drive wheel located distal to the storage reel and thespool, a constant torque spring having a proximal end connected to thespool and a distal end connected to the drive wheel, and a flexiblemember in contact with the drive wheel, the flexible member having aproximal end connected to the storage reel and a length that isconfigured to be driven by the drive wheel toward the distal end of theelongated shaft.

In one embodiment, during the energy storing stage of the firing cycle,the gear train is coupled with the storage reel for rotating the storagereel in a counterclockwise direction, which, in turn, winds the flexiblemember onto the storage reel for retracting the flexible member, which,in turn, rotates the drive wheel in a counterclockwise direction, which,in turn, winds the constant torque spring from the spool onto the drivewheel for storing energy in the constant torque spring.

In one embodiment, at the commencement of the firing cycle, the flexiblemember is fully extended so that a distal end of the flexible member isadjacent the distal end of the elongated shaft. In one embodiment, atthe end of the energy storing stage of the firing cycle, the flexiblemember is wound onto the storage reel and the distal end of the flexiblemember is retracted into the housing.

In one embodiment, a cartridge containing a plurality of stackedsurgical fasteners may be inserted into the housing of the applicatorinstrument. In one embodiment, at the end of the energy storing stage ofthe firing cycle, the distal end of the flexible member is desirablyproximal to the plurality of stacked fasteners.

In one embodiment, during the energy releasing stage of the firingcycle, the at least one gear of the gear train is decoupled from thestorage reel so that the storage reel and the spool are able to rotatefreely relative to the at least one gear of the gear train whereupon theconstant torque spring preferably unwinds from the drive wheel and windsonto the spool for releasing the energy stored in the constant torquespring, which, in turn, rotates the storage reel in a clockwisedirection to unwind the flexible member from the storage reel androtates the drive wheel in a clockwise direction to drive the distal endof the unwound flexible member toward the distal end of the elongatedshaft.

In one embodiment, an insertion tool is secured to the distal end of theflexible member. In one embodiment, the applicator instrument preferablyhas a proximal hard stop located in the housing that contacts theinsertion tool at the end of the energy storing stage of the firingcycle for stopping proximal movement of the flexible member. In oneembodiment, the applicator instrument preferably includes a distal hardstop located at the distal end of the elongated shaft that contacts theinsertion tool at the end of the energy releasing stage of the firingcycle for stopping distal movement of the flexible member.

In one embodiment, the gear train desirably includes a trigger gearconnected to the trigger, a drive gear that meshes with the triggergear, a clutch gear that meshes with the drive gear, and a clutch gearshaft upon which the clutch gear is mounted, whereby the clutch gear andthe clutch gear shaft rotate simultaneously with one another. In oneembodiment, the gear train preferably has a one-way bearing mounted onthe clutch gear shaft, and a mid gear connected to the one-way bearing,whereby the one-way bearing transmits torque to the mid gear whenrotating in a first direction and freewheels relative to the mid gearwhen rotating in an opposite, second direction.

In one embodiment, during the energy storing stage, squeezing thetrigger moves the trigger gear for rotating the drive gear in acounterclockwise direction, which, in turn, rotates the clutch gear in aclockwise direction, which, in turn, rotates the clutch gear shaft in aclockwise direction, which, in turn, rotates the one-way bearing in aclockwise direction, which, in turn, rotates the mid gear in a clockwisedirection, which, in turn, rotates the storage reel in acounterclockwise direction for winding the flexible member onto thestorage reel and retracting the distal end of the flexible member intothe housing.

In one embodiment, the drive gear desirably has an outer perimeter witha first section having gear teeth and a second interrupted tooth sectionhaving no gear teeth. In one embodiment, during the energy storing stageof the firing cycle, the gear teeth on the first section of the outerperimeter of the drive gear mesh with gear teeth on the clutch gear sothat the drive gear and the clutch gear rotate simultaneously with oneanother. In one embodiment, during the energy releasing stage, thesecond interrupted tooth section of the outer perimeter of the drivegear opposes the gear teeth on the clutch gear so that the mid gear isnot coupled with the drive gear and can freewheel relative to the drivegear.

In one embodiment, the one-way bearing transmits torque from the clutchgear shaft to the mid gear as the clutch gear shaft rotates in aclockwise direction and the one-way bearing freewheels relative to theclutch gear shaft as the clutch gear shaft rotates in a counterclockwisedirection.

In one embodiment, the flexible member has a length extending betweenthe proximal and distal ends thereof and openings spaced from oneanother along the length of the flexible member. In one embodiment, thedrive wheel has teeth that mesh with the openings of the flexible memberso that the counterclockwise rotation of the drive wheel moves theflexible member in a proximal direction and clockwise rotation of thedrive wheel moves the flexible member in a distal direction.

In one embodiment, a notch is formed in an outer perimeter of thestorage reel, and a pivoting stop is disposed in the housing adjacentthe outer perimeter of the storage reel. In one embodiment, during theenergy storing stage of the firing cycle, the pivoting stop is movedaway from the outer perimeter of the storage reel by the flexible memberas the flexible member is wound onto the storage reel. In oneembodiment, at the end of the energy releasing stage of the firingcycle, the pivoting stop moves into engagement with the notch at theouter perimeter of the storage reel after the flexible member has beenunwound from the storage reel to prevent further clockwise rotation ofthe storage reel.

In one embodiment, an applicator instrument for dispensing surgicalfasteners preferably has a housing, a cartridge containing a pluralityof stacked surgical fasteners inserted into the housing, an elongatedshaft extending from the housing for dispensing the stacked surgicalfasteners from a distal end of the elongated shaft, an actuator coupledwith the housing, a gear train coupled with the actuator, and a firingsystem configured to be sequentially coupled with and decoupled from thegear train during a firing cycle.

In one embodiment, the firing system preferably includes a storage reel,a spool connected to the storage reel for rotating simultaneously withthe storage reel, a drive wheel located distal to the storage reel andthe spool, a constant torque spring having a proximal end connected tothe spool and a distal end connected to the drive wheel, and a flexiblemember in contact with the drive wheel, the flexible member having aproximal end connected to the storage reel.

In one embodiment, the actuator may be engaged for moving the gear trainto commence the firing cycle. In one embodiment, the firing cycledesirably includes an energy storing stage during which the gear trainis coupled with the storage reel for rotating the storage reel and thespool in a counterclockwise direction, which, in turn, winds theflexible member about the storage reel, which, in turn, rotates thedrive wheel in a counterclockwise direction, which, in turn, winds theconstant torque spring from the spool onto the drive wheel for storingenergy in the constant torque spring.

In one embodiment, the firing cycle preferably includes an energyreleasing stage during which the storage reel and the spool aredecoupled from at least one gear of the gear train whereupon theconstant torque spring unwinds from the drive wheel and winds onto thespool for releasing the stored energy in the constant torque spring,which, in turn, rotates the storage reel in a clockwise direction tounwind the flexible member from the storage reel and rotates the drivewheel in a clockwise direction to drive a distal end of the flexiblemember toward the distal end of the elongated shaft.

In one embodiment, the gear train may include an actuator gear connectedto the actuator, a drive gear that meshes with the actuator gear, aclutch gear that meshes with the drive gear, a clutch gear shaft uponwhich the clutch gear is mounted, whereby the clutch gear and the clutchgear shaft rotate simultaneously with one another, a one-way bearingdisposed on the clutch gear shaft, whereby the clutch gear shafttransmits torque through the one-way bearing when rotating in a firstdirection and the one-way bearing free wheels relative to the clutchgear shaft when the clutch gear shaft rotates in an opposite, seconddirection, and a mid gear connected to the one-way bearing for rotatingsimultaneously with the one way bearing, the mid gear having teeth thatmesh with teeth on the storage reel.

In one embodiment, during the energy storing stage, engaging theactuator moves the actuator gear for rotating the drive gear in acounterclockwise direction, which, in turn, rotates the clutch gear, theclutch gear shaft, the one-way bearing, and the mid gear in a clockwisedirection, which, in turn, rotates the storage reel in acounterclockwise direction for winding the flexible member onto thestorage reel.

In one embodiment, the drive gear has an outer perimeter with a firstsection having gear teeth and a second interrupted tooth section havingno gear teeth. In one embodiment during the energy storing stage of thefiring cycle, the gear teeth on the first section of the drive gear meshwith gear teeth on the clutch gear so that the drive gear and the clutchgear rotate simultaneously with one another. In one embodiment, duringthe energy releasing stage of the firing cycle, the second interruptedtooth section of the drive gear opposes the gear teeth on the clutchgear so that the clutch gear is not meshed with the drive gear.

In one embodiment, the flexible member preferably has a length extendingbetween the proximal and distal ends thereof and openings spaced fromone another along the length of the flexible member. In one embodiment,the drive wheel desirably has teeth that mesh with the openings of theflexible member during proximal and distal movement of the flexiblemember

In one embodiment, a method of dispensing surgical fasteners preferablyincludes providing an applicator instrument having a housing, anelongated shaft extending from the housing, and an actuator coupled withthe housing. In one embodiment, the method includes inserting acartridge containing a plurality of stacked surgical fasteners into thehousing, and disposing a flexible member in the housing with a distalend of the flexible member located adjacent a distal end of theelongated shaft. In one embodiment, the actuator may be engaged forbuilding up energy in a firing system and for retracting the distal endof the flexible member from the distal end of the elongated shaft to afirst location inside the housing, whereupon the retracted distal end ofthe flexible member is proximal to the plurality of stacked surgicalfasteners. In one embodiment, the built up energy is transferred to theflexible member for driving the distal end of the flexible member fromthe first location inside the housing to the distal end of the elongatedshaft, whereby as the distal end of the flexible member moves from thefirst location to the distal end of the elongated shaft the distal endof the flexible member strips a surgical fastener from a bottom theplurality of stacked surgical fasteners and dispenses the strippedsurgical fastener from the distal end of the elongated shaft.

In one embodiment, an applicator instrument for dispensing surgicalfasteners during surgical procedures has a reconfigurable handle thatmay be moved between a pistol configuration, an in-line configuration,and an inverted pistol. The applicator instrument having areconfigurable handle is particularly useful during laparoscopicprocedures such as hernia repair procedures where ergonomics andinstrument maneuverability are critical.

In one embodiment, the applicator instrument includes a distal housingassembly, a proximal handle assembly, a pivoting connection between thedistal housing assembly and the proximal handle assembly, and a lockingelement for securing the distal housing assembly and the proximal handleassembly at a plurality of angular positions relative to each other

In one embodiment, the locking element includes a button located on theproximal handle assembly that may be engaged for enabling the proximalhandle assembly to be pivoted about the distal housing assembly. Theproximal handle assembly is reconfigurable so that it may be placed in aplurality of positions relative to the housing assembly, including apistol configuration, an in-line configuration, or an inverted pistolconfiguration. In one embodiment, the proximal handle assembly can beadjusted through a range of angles between 90 and 180 degrees.

In one embodiment, the applicator instrument desirably includes a geartrain that is used to actuate a firing system for dispensing surgicalfasteners. In one embodiment, the gear train preferably includes a firstportion of a gear train located in the proximal handle assembly, whichis configured to engage a second portion of a gear train located in thedistal housing assembly in order to actuate the firing system. In oneembodiment, at least one gear in the distal housing assembly isconcentric with the axis of rotation of the reconfiguration pivot.

In one embodiment, the proximal handle assembly has a trigger that maybe squeezed for activating the gear train. In one embodiment, duringreconfiguration of the proximal handle assembly relative to the distalhousing assembly, the gear train in the proximal handle assembly isdisengaged from the gear/gear train in the distal housing assembly toallow for the reconfiguration while not affecting the stroke of thetrigger/gear train.

In one embodiment, when the trigger has been squeezed to commence afiring cycle, the reconfiguration button is blocked to preventreconfiguration of the proximal handle assembly relative to the distalhousing assembly during the firing cycle.

In one embodiment, when the reconfiguration button is depressed forchanging the angle of the proximal handle assembly relative to thedistal housing assembly, the trigger or gear train is blocked to preventfiring of the applicator instrument prior to completing thereconfiguration of the proximal handle assembly.

Although the present invention is not limited by any particular theoryof operation, it is believed that providing applicator instrumentshaving reconfigurable handles will improve the ergonomics of surgicalprocedures and improve the maneuverability of the instruments. Forexample, a pistol configuration may be preferred for TotallyExtra-Peritoneal (TEP) Inguinal repair procedures because the trocarsare typically placed near the patient's midline and the surgeon istypically postured to hold instruments above the patient. In contrast,either a pistol or in-line configuration may be preferred forTrans-Abdominal Pre-Peritoneal (TAPP) inguinal and ventral repairs. Forboth of these repairs, the trocars are typically placed near thepatient's side (i.e., lateral placement) and the surgeon will be workingacross the patient's body. On the contra-lateral side, either a pistolor in-line configuration may be advantageous. However, on theipsilateral side, an in-line position provides the benefit of allowingthe surgeon to maintain a neutral wrist position while leveraging thedevice to provide preload to the distal end just before firing.

Thus, in one embodiment, a single applicator instrument having areconfigurable handle may be used for midline and lateral trocarplacements, providing versatility and improved ergonomics.

In one embodiment, a cartridge contains a plurality of surgicalfasteners that are stacked atop one another within the cartridge andurged toward a lower end of the cartridge by a spring. In oneembodiment, an applicator may be used with different cartridges havingdifferent types of surgical fasteners. In one embodiment, an applicatorinstrument may have a cartridge receiving port that is located at theproximal end of the applicator instrument that is adapted to receive thedifferent cartridges. In one embodiment, with an elongated shaft of theapplicator instrument remaining inside a patient, the differentcartridges may be exchanged between firing cycles so that a first typeof surgical fastener may be fired during a first firing cycle and asecond type of surgical fastener may be fired during a second firingcycle. The ability to change cartridges without removing the distal endof the applicator instrument from the patient preferably enhancesefficiency, safety and maintains sterile conditions.

In one embodiment, there is no reconfigurable handle. Instead, thedistal housing assembly is docked directly to the arm of a surgicalrobot. The surgical robot then controls the articulating and firingfunctions through a standard interface on the robotic arm. The user canstill change the cartridge and attach new cartridges to the housingassembly. In this manner, the instrument can be re-loaded or used todeliver a variety of surgical fasteners without changing the applicatorinstrument attached to the robotic arm.

In one embodiment, the proximal handle assembly has a reconfigurationbutton having a reconfiguration slider coupled therewith that isconfigured to engage reconfiguration notches located on the distalhousing assembly. In one embodiment, when the reconfiguration button isdepressed, the reconfiguration slider is moved away from engagement withone of the reconfiguration slots so that the proximal handle assemblymay be pivoted relative to the distal housing assembly. When thereconfiguration button is released, a slider spring normally urges theslider to return to a locked position. In one embodiment, duringreconfiguration of the handle, the gear train between the handle and thehousing is decoupled.

In one embodiment, when the reconfiguration button is depressed, thedeployed reconfiguration button blocks activation of the trigger orcommencement of a firing cycle. Thus, in one embodiment, the applicatorinstrument may not be fired as the position of the handle is beingreconfigured.

In one embodiment, when the trigger is squeezed for moving the geartrain or commencing a firing cycle, the deployed trigger prevents ahandle reconfiguration actuator (e.g., a depressible element or button)from being moved (e.g., depressed). Thus, in one embodiment, theposition of the handle may not be reconfigured as the applicatorinstrument is being fired or after the commencement of a firing cycle.

In one embodiment, an applicator instrument for dispensing surgicalfasteners engages a single surgical fastener from a location at or nearthe proximal end of the instrument and advances the surgical fastener tothe distal end of the instrument. In one embodiment, a driving element,such as a spring, provides a pre-determined force, resulting in aconsistent delivery of the surgical fastener. Over the course of thefiring, this force accelerates the fastener, increasing its velocity andmomentum allowing it to penetrate various meshes and tissues.

In one embodiment, the applicator instrument for delivering surgicalfasteners preferably includes an elongated member, such as an elongatedshaft, having a proximal end and a distal end, a surgical fastener(e.g., a tissue fastener or surgical staple) located adjacent theproximal end of the elongated member, and a mechanism for transportingthe surgical fastener from the proximal end of the elongated member tothe distal end of the elongated member and into tissue.

In one embodiment, the applicator instrument preferably includes acartridge holding one or more surgical fasteners. In one embodiment, aplurality of surgical fasteners are stacked atop or adjacent one anotherwithin a spring-loaded cartridge. In one embodiment, the cartridge maybe positioned adjacent the proximal end of the elongated member.

In one embodiment, the applicator instrument preferably includes anelement for engaging a single surgical fastener held by the cartridge sothat the singulated surgical fastener may be engaged by a firing systemand/or advanced toward the distal end of the elongated member. In oneembodiment, the single surgical fastener may be stripped from the bottomof a stack of surgical fasteners.

In one embodiment, the applicator instrument desirably has a flexiblemember having a distal end for transporting the surgical fastener fromthe proximal end of the elongated member to the distal end of theelongated member. In one embodiment, the flexible member may be made ofplastic, metal, other suitable materials, and/or combinations thereof.In one embodiment, the flexible member may be planar in cross section,or curved in cross section for enhancing the column strength of theflexible member.

In one embodiment, the flexible member has a distal end that pushes thesurgical fastener in a distal direction. In one embodiment, the flexiblemember preferably has a proximal end that may be retracted and stored ina coiled manner (e.g., on a storage reel). In one embodiment, theflexible member may have features for engaging with a drive wheel. Thesefeatures may be holes, pockets, or protrusions. In one embodiment, theone or more drive wheels may have surfaces designed to frictionallyengage with the flexible member.

In one embodiment, the applicator instrument desirably has a drive wheel(e.g., cogged wheel or friction wheel) that engages a section of theflexible member that is proximal to the distal end of the flexiblemember. In one embodiment, the drive wheel may be driven by a constanttorque spring, a torsion spring, an electrically powered motor,mechanically, electrically, electro-mechanically, and/or pneumatically,or a combination of the above. In one embodiment, the drive wheel may bedriven by an external element, for example, by rotary motion from thearm of a robotic surgery system or by compressed air. In one embodiment,the drive wheel may be driven by a stored energy system such as apre-wound spring.

In one embodiment, the flexible member may be directly connected to aconstant torque spring and wound onto the same reel that is coupled withthe constant torque spring, therefore not requiring a drive wheelcomponent. In one embodiment, the flexible member and the constanttorque spring may be layered together on the same coil.

In one embodiment, a spring such as a power spring or a constant torquespring may be connected to the proximal end of the flexible member toaid in retracting the flexible member from an extended position to aretracted position, and to provide tension to prevent billowing of theflexible member away from the reel during operation. In one embodiment,billowing is preferably minimized to reduce drag or losses in thesystem. In one embodiment, the constant torque spring or torsion springdesirably stores energy in response to squeezing a trigger or actuatorcoupled with the handle of the applicator instrument.

In one embodiment, the applicator instrument may have a positive stopcoupled with or that contacts the flexible member or the drive wheel tolimit or control distal movement of the flexible member. In oneembodiment, a positive stop may be located at the distal end of theelongated member or in the housing portion of the applicator instrument,or both. A distal stop provides the benefit of precisely controlling theexpulsion distance that the surgical fastener extends from the distalend of the device. A stop in the housing end of the device can engagedirectly with the flexible member, storage member, or drive wheel. Ifengaged with the drive wheel, it can provide the benefit of reducingcompressive loads on the flexible member when left in the ready to fireposition with the flexible member extended. Alternatively, a stop in thehousing end of the device may engage with the storage reel or flexiblemember to prevent over-rotation of the storage reel and subsequentdamage to the proximal end of the flexible member. For either proximalstop, it is critical to delay the engagement of the stop until after thesurgical fastener has sufficient stroke to embed into tissue. This alsoprovides time for the length of the flexible member to compress,dampening the impact at the proximal stop.

In one embodiment, the flexible member is capable of elasticallycompressing and buckling within the constraints of a guide member, whichpreferably limits the force or stroke that may be applied to thesurgical fastener.

In one embodiment, a cartridge may have tissue fasteners stacked at anyangle within a magazine (e.g. horizontal, vertical or any angle inbetween), relative to the orientation of the elongated shaft.

In one embodiment, surgical fasteners may be singulated or stripped fromthe cartridge utilizing the flexible member. In one embodiment, a distalend of the flexible member includes a protruding portion (e.g., a solidor compressible fin) that pushes/strips a single surgical fastener fromthe cartridge to singulate the surgical fastener and move it into acannula for delivery. In one embodiment, an insertion tool or insertionguide is affixed to the distal end of the flexible member. In oneembodiment, the insertion tool is a feature of the flexible member, suchthat the flexible member and the insertion tool are a single component.The insertion tool may include the fin or a stripper ramp that engages asurgical fastener for stripping the surgical fastener from the bottom ofa surgical fastener stack.

In one embodiment, a dual path arrangement is utilized for advancing asurgical fastener toward a distal end of the elongated member. In oneembodiment, the dual path arrangement includes a first path in which thedistal end of the flexible member strips off a single tissue fastener,and positions the tissue fastener in a staging position on a secondpath. A section of the flexible member proximal to the distal end of theflexible member drops down to the second path for subsequent deploymentof the tissue fastener.

In one embodiment, a rotary motion element may be used to strip a singlesurgical fastener from a cartridge and place the surgical fastener in astaging position for being engaged by a distal end of the flexiblemember.

In one embodiment, an applicator instrument for dispensing surgicalfasteners preferably includes a user actuated trigger that drives a geartrain to rotate a storage reel, which, in turn, retracts a flexiblemember from a distal end of a cannula onto the storage reel. In oneembodiment, the storage reel for the flexible member is a proximalstorage reel located at the proximal end of the distal housing assemblyof the instrument.

In one embodiment, retraction of the flexible member also rotates adrive wheel through a cogged interface or friction interface between theflexible member and the drive wheel. The rotation of the drive wheelwinds a constant torque spring from a spool onto the drive wheel forstoring energy in the constant torque spring. When the flexible memberreaches a pre-determined retracted position behind a surgical fastenercartridge located in the housing or the handle, the gear traindisengages and the portion of the constant torque spring that was woundonto the drive wheel unwinds back to the spool, which, in turn, rotatesthe drive wheel. The rotation of the drive wheel pulls the flexiblemember off the storage reel and drives the flexible member distallythrough the cogged interface and the flexible member strips a tissuefastener from the cartridge and pushes the tissue fastener to the distalend of the cannula (e.g., elongated shaft) and into tissue.

In one embodiment, the applicator instrument may have a drive train thatis directly connected to the drive wheel to wind the constant torquespring from the spool onto the drive wheel. In this embodiment, it ispreferable to utilize a power spring or other means to wind and managethe flexible member as it is urged proximal onto the storage reel.

In one embodiment, the flexible member and surgical fastener may becontinually accelerated as the surgical fastener is pushed down thelength of the elongated shaft. This acceleration increases the velocityand momentum of the fastener, flexible member, and drive wheel system. Aminimum velocity and inertia are necessary to allow the fastener topierce meshes and abdominal wall tissue.

In one embodiment, the flexible member is adapted to push the tissuefastener via geometry that engages with the tissue fastener or via oneor more flat contact surfaces.

In one method of dispensing a surgical fastener, similar to a “bow andarrow” method, the flexible member may be assembled at the distal end ofthe elongated member and, during the firing stroke, be drawn back to thehandle to engage and deliver the tissue fastener. In this embodiment,the flat flexible member remains in a flat configuration during storage,reducing the likelihood that the flexible member will take a permanentset. In one method of dispensing a surgical fastener, referred to as a“coiled snake” method, the flexible member may start in the handle andduring the firing stroke, experience a force to deliver the tissuefastener to the distal end of the elongated member, and then return backto the handle.

In one embodiment, the flexible member may be pulled from and return toa reel located in the handle. In one embodiment, the reel may have apower spring or the flexible member may be self-coiling to help retractthe flexible member and to provide tension to prevent billowing of theflexible member away from the reel during operation. In one embodiment,the drive system may be spring powered, electrically powered, airpowered, hydraulically powered, etc.

The flexible member may be fed through a straight cannula, a curvedcannula, or through a cannula with an articulating end.

In one embodiment, an applicator instrument having an articulatingdistal end may have a bi-stable configuration that utilizes anover-center spring to bias the system toward no articulation of theelongated shaft or full articulation of the elongated shaft. Thebi-stable configuration prevents the distal end of the elongate shaftfrom existing in an intermediate state where the articulation is not asstable.

In one embodiment, the applicator instrument has a user interface (e.g,an articulation control lever) that is in a first position (e.g.,horizontal) when the shaft is not articulated and a second position(e.g., vertical) when the shaft is fully articulated, thereby mirroringthe configuration of the articulated end of the shaft. The userinterface for controlling articulation preferably provides the user withvisual feedback regarding the configuration of the articulated end ofthe shaft when the shaft is inserted into a trocar and is not visible.Although the present invention is not limited by any particular theoryof operation, it is believed that the bi-stable configuration provides auser experience that guides the user toward one of the two articulationpositions and does not allow the user to leave the articulation of theshaft in an intermediate, state. It is also considered that a bi-stablesystem will reduce the mental task load of the surgeon and simplify theuser experience by simplifying the articulation control to a simpletoggle.

In one embodiment, an applicator instrument maintains the integrity of aquantity of surgical fasteners during handling and allows the surgicalfasteners to be removed one at a time for implantation by theinstrument. In one embodiment, a protruding portion of a flexible memberpushes a single tissue fastener from a cartridge to singulate thesurgical fastener and move it into a cannula for delivery from a distalend of an elongated shaft. In one embodiment, surgical fasteners arestacked in the cartridge and a constant force spring is used to move thefasteners toward a staging location in the cartridge. In one embodiment,the surgical fasteners are desirably restricted and only allowed to movein a direction toward the staging location in the cartridge. The staginglocation in the cartridge preferably allows a single surgical fastenerin the staging location to move in a direction parallel to the flexiblemember and then transition into the cannula.

In one embodiment, the distal end of the flexible member includes aninsertion tool having a protruding portion shaped like a “shark fin”that is configured to engage with the back of a surgical fastener in thestaging location of the cartridge and push the surgical fastener intothe cannula for delivery into tissue. In one embodiment, the channelthrough the cannula has a relief groove for the fin.

In one embodiment, a cartridge containing surgical fasteners may haveone or more orientation indicators that direct a user as to the correctorientation for inserting the cartridge into the applicator instrument.In one embodiment, the cartridge may have Poke-a-Yoke features so thatthe cartridge cannot be inserted incorrectly. In one embodiment, thecartridge may have a color indicator that indicates the type of surgicalfasteners loaded into the cartridge. In one embodiment, the colorindicator may be printed onto a label placed on the cartridge or thecolor indicator may be the color of the material used to make thecartridge. In one embodiment, the cartridge may have a snap feature thatprovides tactile feedback that the cartridge is fully/properly insertedinto the applicator instrument. In one embodiment, the applicatorinstrument may have a cartridge release that may be engaged for lockingor inserting the cartridge into the housing of the applicator instrumentor unlocking and removing the cartridge from the housing of theapplicator instrument. In one embodiment, the cartridge release may beon the cartridge itself.

In one embodiment, an applicator instrument has a cartridge system thatutilizes a single linear path to strip a surgical fastener from thecartridge and place the stripped surgical fastener into a properlocation for being delivered from a distal end of the instrument.

In one embodiment, prior to firing the applicator instrument, surgicalfasteners are stacked in a cartridge. A pusher is staged distal to thesurgical fastener, an elevator is aligned with the lower end of thecartridge, and a slide is in a proximal-most position. During a firststage of a firing cycle, as a user squeezes a trigger, the pusher pushesa single surgical fastener out of the cartridge and into the elevator,and the slide moves distally. During a second stage of the firing cycle,as the users fully squeezes the trigger, the pusher stops moving oncethe surgical fastener is fully loaded into the elevator, and theelevator moves down into alignment with the path of the distal end ofthe flexible member, on top of a lower guide. During a third stage of afiring cycle, the slide is in a distal-most position, the elevator isall the way down, and the flexible member moves along the lower guidefor delivering the surgical fastener down the elongated shaft.

In one embodiment, an applicator instrument for dispensing surgicalfasteners has a cartridge system whereby the flexible member utilizes afirst path to strip a surgical fastener from the cartridge and advancethe surgical fastener to the distal end of the elongated shaft, andutilizes a second, different path for returning the flexible member to alocation that is proximal to the cartridge (e.g., a “Racetrack” path).

In one embodiment, an applicator instrument may have a cartridge systemthat utilizes a rotary motion member to strip/singulate a surgicalfastener and place the surgical fastener into a proper location forbeing engaged by a distal end of the flexible member. As a result ofusing a rotary motion element, surgical fasteners may be stacked insidethe cartridge in any orientation relative to the path of the flexiblemember. In one embodiment, the rotary motion may rotate a surgicalfastener through any angle necessary to bring it in-line with the distalend of the flexible member (e.g., 90 degree rotation).

In one embodiment, a cartridge system that stores surgical fasteners ina rotary drum may be side loaded onto an applicator instrument or may betop loaded onto the applicator instrument.

In one embodiment, an applicator instrument for dispensing surgicalfasteners has an elongated shaft that may be articulated for movingbetween a straight configuration and an articulated, curved, or angledconfiguration. In one embodiment, the articulating shaft provides a highlevel of cannula rigidity in both the articulated configuration and thestraight configuration, especially where high axial/lateral forces orpressure is exerted on the distal tip of the cannula during tack/strapapplication in hernia fixation or whenever a counter pressure on thecannula tip is applied (e.g., during mesh manipulation with the distalend of the instrument).

In one embodiment, an applicator instrument for dispensing surgicalfasteners has an articulating shaft. The articulating instrumentpreferably includes an elongated shaft having a proximal end, a distalend, and a longitudinal axis extending between the proximal and distalends. The applicator instrument preferably has a handle attached to theproximal end of the shaft, a cam assembly attached to the handle, atleast one segmented member on the distal end of the elongated shaft, andat least one band having a proximal end and a distal end. In oneembodiment, the distal end of the band is attached to the at least onesegmented member at the distal end of the elongated shaft, and theproximal end of the band is adjustably attached to the cam assembly suchthat rotation of the cam assembly results in movement of the band alongthe longitudinal axis of the shaft resulting in articulation of thesegmented member.

In one embodiment, the proximal end of the band is attached to a yoke,which, in turn, is attached to the cam assembly. In one embodiment, theyoke can pivot around a central axis in response to movement of the camassembly.

In one embodiment, an articulation system preferably includes two bands,each having one end attached to the at least one segmented member onopposite sides of the at least one segmented member and the respectiveproximal ends of the bands are attached to the rotatable yoke.

In one embodiment, a proximal end of an upper band is connected with afirst slider, and the first slider is connected with the rotatable yoke.In one embodiment, a proximal end of a lower band is connected with asecond slider, and the second slider is connected with the rotatableyoke. The connection distance between the first and second sliders andthe yoke may be adjusted for controlling the tension applied onto theupper and lower bands.

In one embodiment, the first slider is adjusted in a proximal directionto impart a first tension on the upper band. Similarly, the secondslider is adjusted in a proximal direction to impart a second tension onthe lower band. In one embodiment, the second tension on the lower bandis less than the first tension on the upper band.

In one embodiment, the cam engages a spring that normally urges the caminto one of two stable positions, a stable first position or a stablesecond position. In one embodiment, moving the cam to the secondposition increases the tension on the upper band while reducing theforce on the lower band, which results in articulation of the at leastone articulating segment at the distal end of the elongated shaft.

In one embodiment, at least one articulating segment is rotatablyattached to the distal end of the elongated shaft so that rotation ofthe shaft is limited or controlled by features on the at least onearticulating segment. In one embodiment, when the cam is in the secondposition, rotation of the distal end of the shaft is limited to apre-defined angle by features on the at least one articulating segment.In one embodiment, the pre-defined rotation is preferably 60 degrees orany value between 0 and 90 degrees.

In one embodiment, an applicator instrument for dispensing surgicalfasteners has an articulating shaft. In one embodiment, the applicatorinstrument includes a proximal shaft section having a proximal end, adistal end, and a longitudinal axis, and a handle attached to theproximal end of the proximal shaft section. The instrument preferablyincludes segmented members coupled with the distal end of the proximalshaft section. Each pair of segmented members accommodates a specificrotation limit. The instrument preferably has two articulation bandsdisposed within the segmented members. In one embodiment, a cam systemis moved from a first position into a second position to tension theupper band while simultaneously releasing the lower band to force thesegmented members into the articulated configuration. In one embodiment,the cam system is moved from the second position back to the firstposition to tension the lower band while simultaneously releasing theupper band to return the segmented members to a non-articulated position(e.g., straight).

In one embodiment, an over-center spring element automatically forcesthe articulating, segmented members into either the articulated orstraight configuration. In one embodiment, the articulation systemincludes adjustment mechanisms for adjusting the level of tensionapplied to the upper and lower bands to provide appropriate tension thatkeeps the shaft at proper rigidity in both the articulated and straightconfigurations.

In one embodiment, the upper and lower band members may be attached torespective upper and lower sliders that may move axially for adjustingthe respective tensions in the upper and lower bands and the rigidity ofthe segmented cannula. In one embodiment, the movement of the upper andlower sliders may be synchronized by coupling the sliders with a yokegiving a center of rotation located halfway between the upper and lowerarticulation bands. In one embodiment, the yoke is driven by a cammember that rotates back and forth (e.g., 90 degrees rotation). In oneembodiment, the cam has a spiral slot which engages with a feature onthe yoke. When the cam member reaches its limits of travel, the slope ofthe spiral slot is sufficiently steep (i.e. <10 degrees) to prevent backdrive, i.e. the addition of external loads to the distal end of thearticulating cannula is unable to force the cam member to rotate.

In one embodiment, the tension forces on the two bands may be adjustedby adjusting the distance between the sliders and rotating yoke.

In one embodiment, the articulating segmented members have a pin-lessdesign, which reduces the risk of foreign matter (e.g., a pin) fromfalling into the abdominal cavity due to pin failure.

In one embodiment, the segmented members preferably have a channel orconduit for the surgical fasteners and the flexible member to passthrough for firing a surgical fastener.

In one embodiment, the adjacent links of the segmented members areadapted to pivot relative to each other for articulating the segmentedmember. In one embodiment, each link has interlocking structures (e.g.,wings) that maintain the rigidity and solid state of the segmentedmembers when in the articulated or straight positions. In oneembodiment, the interlocking structures fully restrict five degrees offreedom and only allow a limited range of rotation around one axis. Inone embodiment, the links of the segmented members have pass ways orslots for receiving the upper and lower articulation bands.

In one embodiment, the distal ends of the upper and lower articulationsbands are welded, joined, attached, hooked, crimped, or pinned onto adistal-most member of the series of segmented members.

In one embodiment, springs may be added to the tensioning adjustmentmeans for tension force relief in the event excessive force isaccidentally applied to the distal end of the articulating cannula. Assuch, less force would be required to displace the distal end of thearticulating cannula assembly, resulting in less stress on thearticulation bands.

In one embodiment, providing an applicator instrument having anarticulating shaft provides many benefits. In one embodiment, providingan articulating shaft improves ergonomics during hernia surgery, enablesipsillateral (same side) mesh manipulation and fixation (reducing therequired number of trocars), enhances maneuverability both inside andoutside the body cavity, improves visualization of the fixation site,and reduces the length of surgical procedures.

In one embodiment, the articulation system requires only a one quarterturn (¼) of the cam or articulation lever(s) for fully articulating theshaft, and only a one quarter return to return the shaft to a straightposition/configuration.

In one embodiment, the articulation system provides a high degree oftension and rigidity, prevents cannula deformation during application,and prevents cannula angle change when the shaft is in the articulatedposition to provide for tip stability and accurate placement for thefixation of surgical fasteners.

These and other preferred embodiments of the present patent applicationwill be described in more detail herein.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1A shows an applicator instrument for dispensing surgical fastenershaving an elongated shaft, a housing connected to a proximal end of theelongated shaft, and a reconfigurable handle pivotally connected withthe housing, the reconfigurable handle being in a pistol configuration,in accordance with one embodiment of the present patent application.

FIG. 1B shows the applicator instrument of FIG. 1A with thereconfigurable handle where the trigger is in a position in-line withthe elongated shaft.

FIG. 2A shows a range of motion for the reconfigurable handle betweenthe pistol configuration of FIG. 1A and the in-line configuration ofFIG. 1B.

FIG. 2B shows the applicator instrument of FIG. 2A with thereconfigurable handle in the pistol configuration and the distal end ofthe elongated shaft in an articulated configuration.

FIG. 3 shows the applicator instrument of FIGS. 1A and 1B used forlateral access and midline access on a patient, in accordance with oneembodiment of the present patent application. Lateral access is typicalfor a ventral or TAPP inguinal repair. Midline access is typical for aTEP inguinal repair.

FIG. 4A shows a cross-sectional view of the applicator instrument ofFIGS. 1A and 1B with the reconfigurable handle in the pistolconfiguration.

FIG. 4B shows a cross-sectional view of the applicator instrument ofFIGS. 1A and 1B with the reconfigurable handle in the in-lineconfiguration.

FIG. 5 shows the reconfiguration mechanism and pivotal connectionbetween housing and a reconfigurable handle of an applicator instrument,in accordance with one embodiment of the present patent application.

FIGS. 6A and 6A-1 show perspective views of a handle reconfigurationactuator and a slider used for changing the position of a reconfigurablehandle relative to a housing, in accordance with one embodiment of thepresent patent application.

FIGS. 6B and 6B-1 show perspective views of the handle reconfigurationactuator and the slider of FIG. 6A with the handle reconfigurationactuator depressed for changing the position of the reconfigurablehandle relative to the housing.

FIG. 7 shows a cross-sectional view of an applicator instrumentincluding a positive stop provided on a gear for preventing squeezing ofa trigger when a handle reconfiguration actuator is depressed, inaccordance with one embodiment of the present patent application.

FIG. 8 shows a cross-sectional view of an applicator instrumentincluding a positive stop provided on a gear for preventing the handlereconfiguration actuator from being depressed after the trigger has beensqueezed for commencing a firing cycle.

FIG. 9A shows a cross-sectional view of an applicator instrument fordispensing surgical fasteners, in accordance with one embodiment of thepresent patent application.

FIG. 9B shows a perspective view of the applicator instrument of FIG.9A.

FIGS. 10A and 10B show a flexible member, a storage reel and a drivewheel of an applicator instrument for dispensing surgical fasteners, inaccordance with one embodiment of the present patent application.

FIG. 11 shows a flexible member and friction drive wheels of anapplicator instrument for dispensing surgical fasteners, in accordancewith one embodiment of the present patent application.

FIG. 12 shows a cross-sectional view of an applicator instrument fordispensing surgical fasteners including a storage reel, a drive wheel,and a proximal positive stop for halting rotation of the storage reel,in accordance with one embodiment of the present patent application.

FIG. 13A shows a cross-sectional view of an applicator instrument fordispensing surgical fasteners prior to the commencement of a firingcycle, in accordance with one embodiment of the present patentapplication.

FIG. 13B shows a cross-sectional view of the applicator instrument ofFIG. 13A during a later stage of the firing cycle, in accordance withone embodiment of the present patent application.

FIGS. 14A and 14A-1 show a magnified view of the firing system shown inFIG. 13B.

FIGS. 14B and 14B-1 show the firing system of FIGS. 14A and 14A-1 duringlater stages of the firing cycle after a surgical fastener has beenstripped from a cartridge.

FIG. 15A shows a cross-sectional view of an applicator instrument fordispensing surgical fasteners prior to the commencement of a firingcycle, in accordance with one embodiment of the present patentapplication.

FIG. 15B shows a cross-sectional view of the applicator instrument ofFIG. 15A during a later stage of the firing cycle, in accordance withone embodiment of the present patent application.

FIG. 16A shows a magnified view of the firing system shown in FIG. 15B.

FIG. 16B shows the firing system of FIG. 16A during a later stage of thefiring cycle.

FIGS. 16C and 16D show a one-way pawl for engaging supplemental teeth ona drive gear, in accordance with one embodiment of the present patentapplication.

FIG. 17 shows a spring-loaded cartridge containing a plurality ofstacked surgical fasteners, in accordance with one embodiment of thepresent patent application.

FIGS. 18A-18D show a method of using a pusher secured to a distal end ofa flexible member for removing a lower-most surgical fastener from acartridge, in accordance with one embodiment of the present patentapplication.

FIGS. 19A-19H show a surgical fastener used to secure prosthetic devicesto tissue, in accordance with one embodiment.

FIG. 20 shows the surgical fastener of FIGS. 19A-19H in a stacked array,in accordance with one embodiment.

FIGS. 21A-21D show a pusher used to dispense the surgical fastener ofFIGS. 17-17H from an applicator instrument, in accordance with oneembodiment.

FIGS. 22A-22D show the pusher of FIGS. 19A-19D engaged with the surgicalfastener of FIGS. 17A-17H.

FIGS. 23 and 24 show a method of guiding a surgical fastener and apusher through a channel of an elongated shaft of an applicatorinstrument, in accordance with one embodiment of the present patentapplication.

FIGS. 25A-25D show a cartridge system of an applicator instrument havingan elevator for aligning a surgical fastener with a distal end of aflexible member, in accordance with one embodiment of the present patentapplication.

FIGS. 26A-26B, 26B-1, and 26C show a cartridge system of an applicatorinstrument having a racetrack element, in accordance with one embodimentof the present patent application.

FIGS. 27A-27C show a cartridge system of an applicator instrument havinga rotary element, in accordance with one embodiment of the presentpatent application.

FIGS. 28A-28B show a side loaded cartridge system of an applicatorinstrument having a rotary drum, in accordance with one embodiment ofthe present patent application.

FIGS. 29A-29B show a top loaded cartridge system of an applicatorinstrument having a rotary drum, in accordance with one embodiment ofthe present patent application.

FIG. 30A shows the applicator instrument of FIG. 1A with thereconfigurable handle in the pistol configuration and the distal end ofthe elongated shaft in an articulated configuration.

FIG. 30B shows the applicator instrument of FIG. 1B with thereconfigurable handle in the in-line configuration and the distal end ofthe elongated shaft in an articulated configuration.

FIG. 31A shows an applicator instrument for dispensing surgicalfasteners having an articulation system for articulating a distal end ofan elongated shaft, in accordance with one embodiment of the presentpatent application.

FIG. 31B shows a distal end of an elongated shaft having an articulatingmember with links capable of pivoting relative to one another, thearticulating member being in a straight configuration, in accordancewith one embodiment of the present patent application.

FIG. 32A shows the articulation system of FIG. 31A with a cam platerotated into a second position for articulating the distal end of theelongated shaft of FIG. 31B.

FIG. 32B shows the distal end of the elongated shaft of FIG. 31B withthe articulating member in a fully articulated configuration.

FIGS. 33A-33C show an applicator instrument having an articulationsystem and a distal end of an elongated shaft being in a straightconfiguration, in accordance with one embodiment of the present patentapplication.

FIGS. 34A-34C show the applicator instrument of FIGS. 33A-33C with theelongated shaft being in a fully articulated configuration.

FIG. 35 shows a perspective view of an intermediate link of thearticulation member of FIG. 31B.

FIG. 36 shows a cross-sectional view of an elongated shaft and aflexible member disposed within an elongated conduit of the elongatedshaft, buckled under compressive load.

FIG. 37 shows a cross-sectional view of a distal end of an elongatedshaft having a positive distal stop for halting distal movement of aflexible member, in accordance with one embodiment of the present patentapplication.

FIG. 38 shows a partial cross-sectional view of an applicator instrumenthaving an articulation system with a tensioning spring coupled with aslider, in accordance with one embodiment of the present patentapplication.

FIG. 39 shows a partial cross-sectional view of an applicator instrumenthaving an articulation system with a first tensioning spring coupledwith a first slider and a second tensioning spring coupled with a secondslider, in accordance with one embodiment of the present patentapplication.

FIGS. 40 and 41A-41D show a gear train for an applicator instrument, inaccordance with one embodiment of the present patent application.

FIGS. 42A-42E show an applicator instrument, in accordance with oneembodiment of the present patent application.

FIGS. 43A-43C show an applicator instrument, in accordance with oneembodiment of the present patent application.

FIGS. 44A-44C show schematic views of a firing system for an applicatorinstrument, in accordance with one embodiment of the present patentapplication.

FIG. 45A shows an applicator instrument having a flexible member in anextended position, in accordance with one embodiment of the presentpatent application.

FIG. 45B shows an applicator instrument having a flexible member in aretracted position, in accordance with one embodiment of the presentpatent application.

FIGS. 46A-46E show a schematic of an applicator instrument having anenergy storing assembly, in accordance with one embodiment of thepresent patent application.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to FIG. 1A, in one embodiment, an applicator instrument 100for dispensing surgical fasteners preferably includes an elongated shaft102 having a proximal end 104 and a distal end 106. In one embodiment,surgical fasteners are advanced from the proximal end 104 to the distalend 106 of the elongated shaft 102 for dispensing the surgical fastenersone at a time from the distal end 106 of the shaft. In one embodiment,the distal end 106 of the elongated shaft 102 is capable of beingarticulated, as will be described in more detail herein.

In one embodiment, the applicator instrument 100 includes a housing 108and a reconfigurable handle 110 that is coupled with a proximal end ofthe housing 108. The applicator instrument 100 includes a trigger 112that may be squeezed toward the reconfigurable handle 110 for dispensinga surgical fastener from the distal end 106 of the elongated shaft 102.

In one embodiment, the applicator instrument 100 includes anarticulation lever 114 that is accessible on the housing 108. Thearticulation lever 114 is desirably movable between a first positionwhereby the distal end 106 of the elongated shaft 102 is in a straightconfiguration, and a second position whereby the distal end 106 of theelongated shaft 102 is in an articulated configuration. The articulationlever 114 may be horizontal in the first position and vertical in thesecond position to provide a visual indicator as to whether the distalend of the elongated shaft is straight or articulated.

In one embodiment, the housing 108 of the applicator instrument 100 isadapted to receive a cartridge 116 that contains a plurality of surgicalfasteners. In one embodiment, the surgical fasteners within thecartridge 116 are stacked atop one another and the cartridge isspring-loaded for urging the stacked surgical fasteners to move towardone end of the cartridge (e.g., in a downward direction). As will bedescribed in more detail herein, the applicator instrument 100preferably includes a flexible member that strips a single surgicalfastener located at a lower end of a stack of surgical fasteners andpushes the surgical fastener through the elongated shaft 102 for beingdispensed from the distal end 106 of the elongated shaft. In oneembodiment, the flexible member serves as a structure for firing ordispensing a surgical fastener from a distal end of the elongated shaft.

In one embodiment, the applicator instrument 100 may be placed in eithera pistol configuration or an in-line configuration, or at a plurality ofpositions located between the pistol and in-line configurations. FIG. 1Ashows the applicator instrument 100 with the handle 110 in a pistolconfiguration. Referring to FIG. 1B, in one embodiment, the handle 110may be selectively rotated relative to the housing 108 for placing thehandle in an in-line configuration. The ability to move the handlebetween a pistol configuration, an in-line configuration, and anyintermediate positions/angles between the pistol and in-lineconfigurations may be particularly useful during various types ofsurgical procedures (e.g., hernia repair procedures) where ergonomicsand instrument maneuverability are critical. In one embodiment, thehandle 110 may be locked at a range of different angular orientationsrelative to the housing 108. In one embodiment, the handle may berotated beyond the pistol or in-line configurations. In one embodiment,as the position of the handle is being reconfigured, a gear train in thehandle 110 is preferably disengaged from a firing system in the housingso that reconfiguring the handle does not affect the trigger, the geartrain, or the firing system.

Referring to FIG. 2A, in one embodiment, the handle 110 of theapplicator instrument 100 is reconfigurable so that it may be positionedin either the pistol configuration or an in-line configuration. In oneembodiment, the handle 110 may also be positioned at intermediatelocations between the pistol configuration and the in-lineconfiguration. In one embodiment, the trigger 112 is coupled to thehandle 110 and moves with the handle as it rotates relative to thehousing 108 between the pistol configuration and the in-lineconfiguration.

In one embodiment, the lower end of the cartridge 116 that contains astack of surgical fasteners is inserted into an opening in the housing108. In one embodiment, the lower end of the cartridge 116 forms asnap-fit connection with the housing 108. In one embodiment, a cartridgerelease button 118 may be depressed for removing the cartridge 116 fromits snap-fit connection with the housing 108. The cartridge releasebutton 118 may be on either the cartridge 116 or the housing 108. In oneembodiment, an applicator instrument does not have a cartridge releasebutton on the housing and a release element is provided on the cartridgethat is inserted into the housing 108. In one embodiment, a proximal end120 of the housing 108 has a concave surface and a distal end 122 of thehandle 110 has a convex surface that guides movement of the handle 110relative to the housing 108 as it rotates between the in-line and thepistol configuration.

Referring to FIGS. 2A and 2B, in one embodiment, the applicatorinstrument 100 preferably includes the elongated shaft 102 that projectsfrom a distal end of the housing 108. The articulation lever 114 may berotated from the first position (i.e., horizontal) shown in FIG. 2A,whereby the distal end of the elongated shaft is straight, and thesecond position (i.e., vertical) FIG. 2B whereby the distal end 106 ofthe elongated shaft 102 is in an articulated configuration. In oneembodiment, the distal end 106 of the elongated shaft 102 may be movedbetween the straight configuration and the articulated configurationwith the handle 110 in either the in-line configuration (FIG. 2A) or thepistol configuration (FIG. 2B). A reconfiguration button 136 may beengaged for moving the handle 110 between the pistol and in-lineconfigurations. The position of the handle may be locked in place byreleasing the reconfiguration button 136.

Referring to FIG. 3, in one embodiment, the position of the handle 110relative to the housing 108 may be selectively reconfigured forimproving ergonomics and instrument maneuverability during a surgicalprocedure. In one embodiment, when the applicator instrument 100 is usedfor trans-abdominal pre-peritoneal (TAAP) inguinal and ventral repairs,a lateral access approach into the patient may be utilized. For lateralaccess, in order to improve ergonomics and instrument maneuverability,the handle 110 may be placed in the in-line configuration relative tothe housing 108. Depending on the location of the target fixation siterelative to the trocar, other handle positions may be used, asnecessary. In contrast, for totally extra-peritoneal (TEP) inguinalrepairs, where trocars are placed near the patient's mid-line, thehandle 110 of the applicator instrument 100 may be placed in the pistolconfiguration relative to the housing 108 for improving ergonomics andinstrument maneuverability. Depending on the location of the targetfixation site relative to the trocar, other handle positions may beused, as necessary. Although the present invention is not limited by anyparticular theory of operation, it is believed that providing applicatorinstruments for dispensing surgical fasteners that have reconfigurablehandles, with one or more positions between the pistol and in-lineconfigurations, dramatically improves the maneuverability and ergonomicsof the applicator instruments when used during laparoscopic procedures.Of particular benefit is the ability to achieve a neutral wrist anglefor the surgeon. Reconfigurable handles also enable more accurateplacement of surgical fasteners, reduced fatigue, and enhanced accuracywhen affixing surgical fasteners. Moreover, reconfigurable handlesenable a surgeon to maintain the entire applicator instrument within asterile field so that a surgeon may avoid moving any portion of theapplicator instrument outside the sterile field as the surgeon maneuversthe applicator instrument into different orientations.

Referring to FIG. 4A, in one embodiment, the applicator instrument 100preferably includes the housing 108 and the reconfigurable handle 110coupled with a proximal end of the housing. The applicator instrument100 includes the elongated shaft 102 that extends distally from a distalend of the housing 108. In one embodiment, the applicator instrumentincludes a gear train 124 that extends between the trigger 112 in thehandle 110 and the housing 108 for activating a firing system todispense a surgical fastener. In one embodiment, the applicatorinstrument has a firing system that meshes with the gear train 124. Inone embodiment, the firing system preferably includes a storage reel 126for storing a flexible member used to dispense a surgical fastener froma distal end of the elongated shaft 102, a drive wheel 128 that engagesthe flexible member for driving the flexible member toward the distalend of the elongated shaft 102 for dispensing a surgical fastener, and aconstant torque spring for storing energy used to drive the drive wheel128.

In one embodiment the housing 108 has an opening adapted to receive acartridge 116 containing a plurality of surgical fasteners stacked inthe cartridge. The surgical fasteners within the cartridge 116 areadapted to be dispensed one at a time from the distal end of theelongated shaft 102. During a firing cycle, each time the trigger 112 issqueezed toward the handle 110, a firing cycle commences for firing asingle surgical fastener from the distal end of the elongated shaft 102.In one embodiment, the applicator instrument 100 includes a triggerreturn spring 130 having a lower end 132 connected with the handle 110and an upper end 134 connected with the trigger 112. In one embodiment,the trigger return spring 130 normally urges the trigger to return tothe open position shown in FIG. 4A.

In one embodiment, an applicator instrument may be capable of receivingdifferent cartridges containing surgical fasteners having differentproperties. In one embodiment, the different properties for the surgicalfasteners may relate to the material, absorption time, size, length,width, leg length, barb length, number of barbs on a leg, curved legs,straight legs, color, opacity, cartridge quantity, etc. In oneembodiment, a first cartridge may contain surgical fasteners having afirst property (e.g., legs having a first length) and a second cartridgemay contain surgical fasteners having a second property (e.g., legshaving a longer second length) that is different than the firstproperty. The first cartridge may be inserted into the applicatorinstrument for dispensing the first surgical fasteners into the patient.After completing the fixation necessary with the first surgicalfasteners, the first cartridge may be decoupled from the applicatorinstrument and replaced by the second cartridge for dispensing thesecond surgical fasteners into the patient. A portion of the applicatorinstrument (e.g., the elongated shaft), may remain inside the patient asthe cartridges are changed, which preferably minimizes the time requiredto perform a surgical procedure and enhances sterile conditions. Afterexchanging cartridges, the applicator device is immediately ready to usethe second set of surgical fasteners. Additional cartridges havingadditional properties may be used during a single surgical procedure. Inone embodiment, multiple surgical fastener types may be provided in asingle cartridge.

In one embodiment, the applicator instrument 100 preferably includes ahandle reconfiguration actuator 136 (e.g., a depressible button) that isprovided on the reconfigurable handle 110. In FIG. 4A, the handlereconfiguration actuator 136 is depressed so that the handle 110 may berotated between the pistol configuration shown in FIG. 4A and thein-line configuration shown in FIG. 4B. Referring to FIGS. 4A and 4B, inone embodiment, the trigger 112 is coupled with the reconfigurablehandle 110 so that the trigger rotates with the handle as it movesbetween the pistol configuration and the in-line configuration.

In one embodiment, the handle 110 may be rotated relative to the housing108 when the handle reconfiguration actuator 136 is depressed or moved.When the handle reconfiguration actuator 136 is not depressed, thehandle 110 is locked in place relative to the housing 108 and may notmove between the pistol and in-line configurations. In one embodiment,the gear train extends between the handle and the housing in order toactuate the firing system. The handle includes the trigger 112 foractivating the gear train 124. When the trigger is pulled, the geartrain 124 is activated for commencing a firing cycle and allowing asurgical fastener to be dispensed from a distal end of the elongatedshaft 102. In one embodiment, the gear train 124 is initially disengagedwhen the trigger 112 is open. In one embodiment, when the trigger 112 isactuated (e.g., squeezed), the gear train 124 engages the firing system.Because the gear train 124 is initially disengaged, the handle 110 canbe reconfigured between the pistol configuration and the in-lineconfiguration without affecting the stroke of the trigger/gear train. Inone embodiment, a one-way bearing meshes the gear train with the firingsystem during a first stage of a firing cycle, and the one-way bearingdecouples the gear train from the firing system during a later stage ofthe firing cycle. In another embodiment, when the handle reconfigurationactuator 136 is depressed for rotating the handle 110, a portion of thegear train located in the handle 110 is disengaged, allowing for thereconfiguration of the handle relative to the housing and not affectingthe stroke of the trigger/gear train. In one embodiment, when thetrigger 112 is squeezed for activating a firing cycle, the handlereconfiguration actuator 136 is blocked from being depressed so as toprevent reconfiguration of the handle relative to the housing during afiring cycle. In one embodiment, when the handle reconfigurationactuator 136 is depressed, the trigger and/or gear train 124 is blockedto prevent firing of a surgical fastener prior to completing thereconfiguration of the handle relative to the housing.

Referring to FIG. 5, in one embodiment, a proximal end of the housing108 includes a series of spaced reconfiguration notches 138A-138G thatare utilized for positioning the handle 110 at differentconfigurations/angles relative to the housing 108. In one embodiment,the reconfiguration notches 138A-138G are arrayed in an arc-shapedpattern at the proximal end of the housing 108. In one embodiment, theapplicator instrument 100 includes a slider 140 that extends between thehandle reconfiguration actuator 136 and the reconfiguration notches138A-138G at the proximal end of the housing 108. The slider 108includes a proximal end 142 that is engaged by an underside of thehandle reconfiguration actuator 136 and a distal end 144 that is adaptedto be seated within the reconfiguration notches 138A-138G. In oneembodiment, when the handle reconfiguration actuator 136 is depressed,the distal end 144 of the slider 140 disengages from one of thereconfiguration notches 138A-138G, which enables the handle 110 to berotated relative to the housing 108. When the handle reconfigurationactuator 136 is released, the distal end 144 of the slider 140 is seatedwithin one of the reconfiguration notches 138A-138G for locking theposition of the handle 110 relative to the housing 108 so that thehandle may not be pivoted relative to the housing.

Referring to FIGS. 6A and 6A-1, in one embodiment, when the handlereconfiguration actuator 136 is in an extended, undepressed position,the distal end 144 of the slider 140 sits within the reconfigurationnotch 138A for locking the position of the handle 110 relative to thehousing 108. A slider return spring 146 normally urges the distal end144 of the slider 140 to be seated within one of the reconfigurationnotches 138A-138G (FIG. 5).

Referring to FIGS. 6B and 6B-1, when the handle reconfiguration actuator136 is depressed, and underside of the handle reconfiguration actuatorengages the proximal end 142 of the slider 140 for overcoming the forceof slider return spring 146 and shifting the distal end 144 of theslider 140 away from the reconfiguration notch 138A. As the distal end144 of the slider 140 moves away from the reconfiguration notch 138A,the slider return spring 146 is compressed. With the handlereconfiguration actuator 136 depressed, the handle 110 may be rotatedrelative to the housing 108 for aligning the distal end 144 of theslider 140 with any one of the other reconfiguration notches 138A-138G(FIG. 5). When the handle 110 has been positioned at a desiredconfiguration relative to the housing 108, the handle reconfigurationactuator 136 may be released, whereupon the slider return spring 146urges the slider 140 and the distal end 144 of the slider 140 back intoengagement with one of the reconfiguration notches 138A-138G on thehousing 108 for locking the handle in place. The handle 110 is locked inplace relative to the housing 108 as long as the distal end 144 of theslider 140 is seated in one of the reconfiguration notches 138A-138G(FIG. 5).

Referring to FIG. 7, in one embodiment, the handle reconfigurationactuator 136 has a locking projection 150 that extends from an undersidethereof. In one embodiment, the gear train 124 preferably has a drivegear 177 having a raised ring 152 that projects above a major face ofthe drive gear. The raised ring 152 on the drive gear 177 is notcontinuous and includes a ring opening 154 that is normally aligned withthe locking projection 150 of the handle reconfiguration actuator 136when the trigger 112 is in an extended/open position. In one embodiment,when the handle reconfiguration actuator 136 is depressed for changingthe configuration of the handle 110 relative to the housing 108, thelocking projection 150 extends into the ring opening 154 of the raisedring 152 of the drive gear 177, which blocks the trigger 112 from beingpulled toward the handle 110. Thus, the firing system including the geartrain 124 of the applicator instrument may not be activated when thehandle reconfiguration actuator 136 is depressed for reconfiguring theposition of the handle 110 relative to the housing 108.

Referring to FIG. 8, in one embodiment, when the trigger 112 is squeezedtoward the handle 110 for commencing a firing cycle, the handlereconfiguration actuator 136 may not be depressed for reconfiguring theposition of the handle 110 relative to the housing 108. In oneembodiment, the drive gear 177 includes the raised ring 152 projectingfrom a major face thereof. As the trigger 112 is pulled toward thehandle 110, the drive gear 177 rotates in a counterclockwise directionso that the closed portion of the raised ring 152 is aligned with thelocking projection 150 extending from an underside of the handlereconfiguration actuator 136. As a result, the handle reconfigurationactuator 136 is blocked from being depressed by the engagement of thelocking projection 150 with the outer perimeter of the raised ring 152of the drive gear 177.

Referring to FIGS. 9A and 9B, in one embodiment, an applicatorinstrument 100 for dispensing surgical fasteners includes a housing 108and a handle 110 that may be reconfigured relative to the housing 108for moving the handle 110 between a pistol configuration and an in-lineconfiguration. The applicator instrument 100 includes a firing systemfor dispensing a surgical fastener from a distal end of an elongatedshaft 102 that projects from a distal end of the housing 108. In oneembodiment, the firing system is activated by a trigger 112 that may besqueezed toward the handle 110. In one embodiment, the firing systemincludes a gear train 124 that extends between the trigger 112 and thehousing 108. In one embodiment, portions of the gear train may bedisposed within both the handle 110 and the housing 108. The firingsystem for the applicator instrument 100 desirably includes a storagereel 126 that is adapted to store a flexible member 160 and a drivewheel 128 that engages the flexible member 160 for driving the flexiblemember toward the distal end of the elongated shaft 102. The flexiblemember preferably engages surgical fasteners for dispensing the surgicalfasteners from the distal end of the elongated shaft. A cartridge 116containing a plurality of surgical fasteners may be inserted into anopening in the housing 108 to provide surgical fasteners for the firingsystem. In one embodiment, a plurality of surgical fasteners are arrayedin a stack within the cartridge 116 and a lower-most one of the surgicalfasteners in the stack is dispensed from a distal end of the elongatedshaft 102 each time the trigger 112 is squeezed for activating a firingcycle. A distal-most end of the flexible member is adapted to strip thelower-most surgical fastener from the stack of surgical fasteners withinthe cartridge 116 and advance the singulated surgical fastener towardthe distal end of the elongated shaft 102 for dispensing the surgicalfastener from the applicator instrument. In one embodiment, the storagereel 126 rotates in a counterclockwise direction for winding theflexible member 160 onto the storage reel. During the firing cycle, thestorage reel 126 rotates in a clockwise direction as the flexible memberis driven in a distal direction by the drive wheel 128, also rotating ina clockwise direction.

Referring to FIGS. 10A and 10B, in one embodiment, the flexible member160 has a proximal end 162 that is attached to the storage reel 126.When the storage reel 126 rotates in a counterclockwise direction, theflexible member 160 is wound about the storage wheel. When the storagewheel 126 rotates in a clockwise direction, the flexible member 160 isunwound from the storage reel 126 so that it may be advanced toward thedistal end of the elongated shaft. In one embodiment, the storage reel126 has a notch 164 (FIG. 10A) formed in the outer perimeter thereof. Inone embodiment, the notch 164 may be engaged by a pivoting stop 170located in the housing for preventing further clockwise rotation of thestorage reel.

In one embodiment, the drive wheel 128 has a plurality of gear teeth 166that project from an outer perimeter thereof that engage a series ofopenings 168 formed in the flexible member 160. In one embodiment, whenthe drive wheel 128 rotates in a clockwise direction (from theperspective shown in FIG. 10A), the teeth 166 engage the openings 168 onthe flexible member 160 for driving the flexible member towards thedistal end of the elongated shaft. In one embodiment, a constant torquespring 172 is connected between a spool 139 and the drive wheel 128. Inone embodiment, retraction of the flexible member 160 rotates the drivewheel 128 in a counterclockwise direction (from the perspective shown inFIG. 10A), which, in turn, winds the constant torque spring 172 from thespool 139 onto the drive wheel 128. This action stores potential energyas the constant torque spring 172 wants to return to the spool 139.

Referring to FIG. 11, in one embodiment, rather than using the coggeddrive wheel shown in FIG. 10, the firing system may include a pair offriction wheels 128A′, 128B′ having opposing friction surfaces 166A′that engage top and bottom surfaces of a flexible member 160′ fordriving the flexible member 160′ toward a distal end of an elongatedshaft. In one embodiment, the pair of friction wheels are geared to eachother to reduce the potential for slippage.

Referring to FIG. 12, in one embodiment, the applicator instrument 100includes the proximal, pivoting stop 170 adapted to engage the notch 164formed on the outer perimeter of the storage reel 126. The proximalpositive stop 170 engages the notch 164 for preventing further clockwiserotation of the storage reel 126 so as to halt further distal movementof the flexible member 160 (FIG. 10A) toward the distal end of theelongated shaft. In one embodiment, as the flexible member 160 is woundonto the storage reel 126, the proximal positive stop 170 is adapted topivot away from the outer perimeter of the storage reel 126 when thestorage reel is rotated in a counterclockwise direction, however, as theflexible member is driven toward the distal end of the elongated shaft,the proximal stop 170 is adapted to pivot into engagement with the notch164 of the storage reel 126 for halting further clockwise rotation ofthe storage reel 126.

Referring to FIG. 13A, in one embodiment, at the commencement of afiring cycle, the trigger 112 is in an extended position, away from thehandle 110. The flexible member 160 preferably extends to the distal endof the elongated shaft 102. Surgical fasteners (not shown) are desirablystacked within the cartridge 116, which, in turn, is inserted into thehousing 108. The firing system includes a constant torque spring 172(FIG. 10B) that is connected between a spool 139 (FIG. 10B) coupled withthe storage reel 126 and the drive wheel 128.

Referring to FIG. 13B, in one embodiment, as a user squeezes the trigger112 toward the handle 110, the gear train 124 between the trigger 112and the storage reel 126 re-meshes and begins rotating the storage reel126 in a counterclockwise direction for retracting the distal end of theflexible member 160 from the distal end of the elongated shaft 102 andwinding the flexible member 160 onto the storage reel 126 so that thedistal end of the flexible member 160 is proximal to the cartridge 116and the surgical fasteners stacked within the cartridge. Retraction ofthe flexible member 116 rotates the drive wheel 128 in acounterclockwise direction, which, in turn, winds the constant torquespring 172 from the spool 139 (FIG. 10B) onto the drive wheel 128. Thisaction stores potential energy in the constant torque spring so that theconstant torque spring wants to return to the spool 139 (FIG. 10B).

Referring to FIG. 14A, in one embodiment, an insertion tool 174, adaptedto engage a surgical fastener, is attached to the distal end of theflexible member 160. In FIG. 14A, the insertion tool 174 is positionedproximal to the cartridge 116 and the plurality of surgical fastenersthat are stacked within the cartridge. In the stage of the firing cycleshown in FIG. 14A, the proximal end of the flexible member 160 has beenwound onto the storage reel 126 and the constant torque spring 172 hasbeen wound from the spool 139 (FIG. 10B) onto the drive wheel 128.

Referring to FIG. 14A-1, in one embodiment, when the trigger 112 hasalmost reached a fully squeezed position (i.e., almost fully closed),the insertion tool 174 attached to the distal end of the flexible member160 has been retracted to a position that is proximal to the cartridge116 and the stack of surgical fasteners disposed within the cartridge.In one embodiment, the housing 108 preferably includes a proximal hardstop 173 that engages the insertion tool 174 for preventing furtherproximal movement of the insertion tool 174. At this stage of the firingcycle, the teeth on a large drive gear 177 are about to disengage fromthe teeth on a smaller clutch gear 179 for decoupling the storage reel126 from the large drive gear 177.

Referring to FIGS. 14B and 14B-1, at the end of rotation of the largedrive gear 177 of the drive train 124, the large drive gear 177disengages from the smaller clutch gear 179 for removing the tensileconstraint on the flexible member 160. In one embodiment, once the gearteeth on the large drive gear 177 no longer engage the gear teeth on thesmaller clutch gear 179, the drive wheel 128 and the storage reel 126are decoupled from the large drive gear 177 and are free to rotaterelative to the large drive gear 177, at which point, the energy storedin the constant torque spring 172 (FIG. 14A) is released for rotatingthe drive wheel 128 in a clockwise direction, which, in turn, drives theflexible member 160 and the insertion tool 174 toward the distal end ofthe elongated shaft 102. At this stage, the constant torque spring 172applies a constant force to the drive wheel 128, resulting in constantacceleration of the drive wheel 128, the flexible member 160, theinsertion tool 174, and the storage reel 126. As the drive wheel 128rotates in a clockwise direction, the teeth 166 on the drive wheel 128engages the openings on the flexible member 160 for driving the flexiblemember in a distal direction. As the insertion tool 174 is drivendistally, it strips a surgical fastener from the bottom of the stack ofsurgical fasteners disposed within the cartridge 116 and advances thestripped surgical fastener toward the distal end of the elongated shaft102 for being dispensed into tissue (e.g., to secure a surgical mesh totissue). Referring to FIG. 14B-1, in one embodiment, the pivoting stop170 is seated in the notch 164 of the storage reel 126 for haltingfurther clockwise rotation of the storage reel, which, in turn, haltsdistal movement of the flexible member 160.

Referring to FIGS. 15A and 15B, in one embodiment, prior to thecommencement of a firing cycle, the insertion tool 174 attached to thedistal end of the flexible member 160 is located within the housing 108of the applicator instrument 100 and is proximal to the surgicalfastener stack 178 within the cartridge 116. The surgical fastener stack178 is located within the cartridge 116. The flexible member 160 iswound onto the storage reel 126 and energy is stored in drive wheel 128prior or during each firing cycle. This system may be referred to ashaving a “coiled snake” firing system. During the trigger actuation, theenergy is released to accelerate the drive wheel 128 and flexible member160 toward the distal end of the instrument.

Referring to FIG. 15B and 16A, in one embodiment, the user squeezes thetrigger 112 toward the handle 110 so that the gear train 124 rotates thedrive wheel 128 in a counterclockwise direction for winding the constanttorque spring 172 from the spool 139 (FIG. 10B) onto the drive wheel128.

Referring to FIG. 16B, in one embodiment, during a later stage of thefiring cycle, the gear train 124 may decouple the trigger from thestorage reel 126, thereby freeing the storage reel 126 to rotate so thatthe constant torque spring can rotate the drive wheel 128 in a clockwisedirection for advancing the flexible member toward the distal end of theelongated shaft. In one embodiment, the constant torque spring 172 movesfrom the drive wheel 128 back to the spool 139 (FIG. 10B) of the storagereel 126 for rotating the drive wheel 128 in a clockwise direction anddriving the flexible member 160 and the insertion tool 174 at the distalend of the flexible member 160 toward the distal end of the elongatedshaft 102. As the insertion tool is driven distally, the insertion tool174 desirably strips a lower-most surgical fastener 176 from the bottomof the surgical fastener stack 178 within the cartridge 116 and advancesthe stripped surgical fastener toward the distal end of the elongatedshaft 102.

Referring to FIGS. 16C and 16D, in one embodiment, a one-way pawl 125engages with a member of the gear train 124. In one embodiment, a drivegear 177 has teeth 129 that are adapted to engage the pawl 125. The pawl125 preferably ensures that a user must fully squeeze and fully releasethe trigger. If the trigger is partially deployed in either direction,the pawl 125 will desirably engage the gear train and prevent the geartrain from moving in the opposite direction. Once the trigger reachesthe limits of its travel, the pawl 125 will be spring loaded via a pawlreset spring 127 to allow the pawl to reset for travel in the oppositedirection. In one embodiment, a drive gear has teeth 129 that areadapted to engage the pawl 125 to prevent partial squeezing of thetrigger.

Referring to FIG. 17, in one embodiment, a cartridge 116 contains astack of surgical fasteners 178. An outer surface of the cartridge 116includes a catch 180 that enables the cartridge 116 to be snap-fit intothe housing 108 (FIG. 2A) of an applicator instrument. In oneembodiment, a cartridge release button 118 (FIG. 2A) may be depressedfor disengaging from the catch 180 so that the cartridge 116 may beremoved from the snap-fit connection with the housing. In oneembodiment, the user may depress the catch 180 so that the cartridge 116may be removed from the snap-fit connection with the housing 108. In oneembodiment, the cartridge 116 includes a constant force spring 182 thaturges the surgical fasteners 178 toward the lower end 184 of thecartridge 116. In one embodiment, the constant force spring pulls on acartridge sled 183, which pushes on the stack of surgical fasteners.

Referring to FIG. 18A, in one embodiment, the insertion tool 174attached to the distal end of the flexible member 160 is adapted tostrip a lower-most surgical fastener 176 from the bottom of the surgicalfastener stack 178. The insertion tool 174 desirably includes a fin 175that projects above a main body of the insertion tool 174 at adistal-most end of the insertion tool for engaging a rear surface of thelower-most surgical fastener 176. The insertion tool 174 is adapted tostrip the lower-most surgical fastener 176 from the bottom of the stackand advance the surgical fastener through a conduit 105 of the elongatedshaft 102 for dispensing the surgical fastener 176 from the distal-mostend of the elongated shaft.

Referring to FIG. 18B, in one embodiment, the fin 175 of the insertiontool 174 contacts the proximal or trailing end of the lower-mostsurgical fastener 176 for stripping the surgical fastener 176 from thebottom of the stack 178. Referring to FIGS. 18C and 18D, in oneembodiment, the flexible member 160 and the insertion tool 174 movedistally for guiding the stripped surgical fastener 176 into the conduit105 of the elongated shaft 102. As shown in FIG. 18C, ramped features187 within the track simultaneously bias the tips of the surgicalfastener and the inner crown of the surgical fastener. These rampedfeatures ensure that the entire surgical fastener drops vertically withminimal angling. Angling of the surgical fastener should be avoided toreduce opportunities for jamming. The flexible member 160 continues tomove distally until the insertion tool 174 dispenses the surgicalfastener 176 from the distal-most end of the elongated shaft 102.

Referring to FIGS. 19A-190, in one embodiment, a surgical fastener 220for securing prosthetic devices (e.g., surgical mesh) to tissuepreferably includes a first leg 222A having a proximal end 224A and adistal end 226A. In one embodiment, a first cross sectional area CS1adjacent the proximal end 224A of the first leg 222A is greater than asecond cross sectional area CS2 adjacent the distal end 226A of thefirst leg 222A. In one embodiment, the first leg 222A tapers inwardlybetween the proximal end 224A of the first leg 222A and the distal end226A of the first leg 222A. In one embodiment, the largest crosssectional area of the first leg is adjacent the proximal end 224A of thefirst leg and the first leg tapers inwardly between the proximal end andthe distal end thereof.

In one embodiment, the first leg 222A extends along a first longitudinalaxis A₁. In one embodiment, the first leg 222A includes an insertion tip228A located at the distal end 226A of the first leg. In one embodiment,the insertion tip 228A has a distal-most point 229A. In one embodiment,the insertion tip 228A is asymmetrical so that it skews outwardlyrelative to the longitudinal axis A₁ of the first leg 222A.

In one embodiment, the surgical fastener 220 preferably includes asecond leg 222B having a proximal end 224B and distal end 226B. Thesecond leg 222B desirably has a first cross sectional area CS1′ adjacentthe proximal end 224B that is greater than a second cross sectional CS2′adjacent the distal end 226B. In one embodiment, the second leg 222Btapers inwardly between the proximal end 224B of the second leg 222B andthe distal end 226B of the second leg 222B. In one embodiment, thesecond leg 222B has an insertion tip 228B located at the distal endthereof. In one embodiment, the insertion tip 228B has a distal-mostpoint 229B. In one embodiment, the second leg 222B extends along asecond longitudinal axis A₂ that is parallel to the first longitudinalaxis A₁ of the first leg 222A. In one embodiment, the insertion tip 228Bon the second leg 222B is asymmetrical and skews outwardly relative tothe second longitudinal axis A₂ of the second leg 222B.

In one embodiment, the first leg 222A includes a distal barb 230A. Inone embodiment, the distal barb 230A is positioned adjacent the distalend 226A of the first leg 222A and is proximal to the distal-most point229A on the insertion tip 228A. The distal barb 230A preferably extendsinwardly toward the second leg 222B. In one embodiment, the first leg222A has a proximal barb 232A that also extends inwardly toward thesecond leg 222B. In one embodiment, the proximal barb 232A on the firstleg 222A is located between the proximal end 224A of the first leg 222Aand the distal barb 230A. In one embodiment, the proximal barb 232A islocated about halfway between the proximal end 240A and the distal end226A of the first leg 222A.

In one embodiment, the second leg 222B of the surgical fastener 220preferably includes a distal barb 230B that extends inwardly toward thefirst leg 222A. In one embodiment, the distal barbs 230A, 230B on therespective first and second legs 222A, 222B oppose one another, extendtoward one another, and are aligned with one another along the lengthsof the respective first and second legs 222A, 222B.

In one embodiment, the second leg 222B includes a proximal barb 232Bthat extends inwardly toward the first leg 222A. In one embodiment, theproximal barbs 232A, 232B on the respective first and second legs 222A,222B extend toward one another, oppose one another, and are aligned withone another along the lengths of the respective first and second legs222A, 222B.

In one embodiment, the surgical fastener 220 extends along a centralaxis A₃ that bisects the surgical fastener 220 into a first halfincluding the first leg 222A with the associated barbs 230A, 232A, and asecond half including the second leg 222B with the associated barbs230B, 232B. The central axis A₃ is preferably parallel to both the firstlongitudinal axis A₁ of the first leg 222A and the second longitudinalaxis A₂ of the second leg 222B. In one embodiment, the central axis A₃bisects the surgical fastener 220 for splitting the surgical fastenerinto two evenly sized parts and is equidistant from the firstlongitudinal axis A₁ of the first leg 222A and the second longitudinalaxis A₂ of the second leg 222B.

In one embodiment, the distal barb 230A on the first leg 222A has aninner tip 234A and the distal barb 230B on the second leg 222B has aninner tip 234B. The respective inner tips 234A, 234B define a distanceD₁ that extends along an axis that is perpendicular to the central axisA₃ of the surgical fastener 220.

In one embodiment, the proximal barb 232A on the first leg 222A has aninner tip 236A and the proximal barb 232B on the second leg 222B has aninner tip 236B. The inner tips 236A, 236B define a distance D₂ thatextends along an axis that is perpendicular to the central axis A₃ ofthe surgical fastener 220. In one embodiment, the distance D₁ betweenthe inner tips 234A, 234B of the respective distal barbs 230A, 230B isgreater than the distance D₂ between the inner tips 236A, 236B of theproximal barbs 232A, 232B. In one embodiment, the distance D₁ is about0.030 inches and the distance D₂ is about 0.025 inches.

In one embodiment, the first and second insertion tips 228A, 228B areadvanced into tissue followed by the first and second distal barbs 230A,230B to form two spaced tissue openings. In one embodiment, the twotissue openings will be about 0.030 inches apart from one another, whichis equal to the distance D₁ between the inner tips 234A, 234B of thefirst and second distal barbs 230A, 230B. In one embodiment, the firstand second proximal barbs 232A, 232B are closer together than are thefirst and second distal barbs 234A, 234B, which enables the first andsecond proximal barbs 236A, 236B to grip onto the side walls of thetissue openings previously formed by the first and second distal barbs230A, 230B. Thus, an important tissue anchoring benefit is gained byproviding proximal barbs 232A, 232B that are closer together than thedistal barbs 230A, 230B.

In one embodiment, the surgical fastener 220 may be made of absorbableand/or non-absorbable materials. Preferred absorbable materials includePDS, PDS/lactide-glycolide blends, PLA, etc. In one embodiment, eachsurgical fastener is sized to fit inside of a 5 mm outer diameter tube(a typical trocar cannula dimension). The surgical fastener isfabricated by molding, however, with small modifications, otherprocesses such as casting, stamping, and machining may be used. In oneembodiment, the surgical fasteners may be extruded into a general shape,and then formed. In one embodiment, the surgical fasteners may beprinted using a 3-D printer.

Referring to FIGS. 19A-19D, in one embodiment, the surgical fastener 220preferably includes a bridge 238 that interconnects the proximal ends224A, 224B of the respective first and second legs 222A, 222B. Thecentral axis A₃ of the surgical fastener 220 desirably bisects thebridge. In one embodiment, the bridge 238 includes a major surface 240that extends adjacent the proximal ends 224A, 224B of the first andsecond legs 222A, 222B, and a crown 242 that projects proximally fromthe major surface 240 to define a proximal-most portion of the surgicalfastener 220. In one embodiment, the major surface 240 is flat. As willbe described in more detail herein, the major surface 240 is preferablyengaged by a distal end of a flexible member or by an insertion toolsecured to the distal leading of a flexible member for applying aninsertion force to the surgical fastener and controlling the orientationof the surgical fastener as the surgical fastener is dispensed from anapplicator instrument. In one embodiment, the crown 242 includes acenter section 244 that spans the thickness T₁ (FIG. 19D) of thesurgical fastener 220 and first and second lateral flanges 246A, 246Bthat extend laterally from the center section 244.

Referring to FIGS. 19C and 19D, in one embodiment, the surgical fastener220 has a length L₁ of about 0.248 inches, a width W₁ of about 0.160inches, and a thickness T₁ of about 0.050 inches. In one embodiment, thewidth W₁ of the surgical fastener 220 is the same at both the proximaland distal ends thereof, and the width W₁ remains constant between theproximal and distal ends of the surgical fastener to aide with feeding.In other words, the width W₁ defined by the distance between the outersurfaces of the first and second legs 222A, 222B at the proximal ends224A, 224B of the legs equals the distance between the outer surfaces ofthe insertion tips 228A, 228B at the distal ends of the first and secondlegs 222A, 222B. In one embodiment, the cross-sectional areas of thelegs decrease when moving from the proximal ends to the distal ends ofthe respective first and second legs 222A, 222B, however, the width W₁of the surgical fastener remains constant between the proximal anddistal ends of the first and second legs.

In one embodiment, the center section 244 of the crown 242 has a widthW₂ of about 0.057 inches and the laterally extending flanges 246A, 246Bdefine a width W₃ of about 0.120 inches.

Referring to FIGS. 19D and 19E, the center section 244 of the crown 242defines a thickness T₂ that equals the thickness T₁ of the surgicalfastener 220. In one embodiment, the laterally extending flanges 246A,246B have a thickness T₃ of about 0.020 inches.

Referring to FIGS. 19E and 19F, in one embodiment, the crown 242 at theproximal end of the surgical fastener 220 desirably includes the centersection 244 and the first and second laterally extending flanges 246A,246B that extend laterally from the center section 244. The majorsurface 240 of the bridge extends around the sides of the respectivefirst and second laterally extending flanges 246A, 246B. In oneembodiment, a first section 240A of the major surface 240 extends aroundthe first laterally extending flange 246A and has a C-shape, and asecond section 240B of the major surface 240 extends around the secondlaterally extending flange 246B and has a C-shape. The C-shaped firstand second sections 240A, 240B of the major surface 240 have the sameshape and configuration and oppose one another on opposite sides of thecenter section 244. In one embodiment, the C-shaped sections 240A, 240Bare aligned with the respective longitudinal axes A₁, A₂ of the firstand second legs 222A, 222B (FIG. 19A).

Referring to FIG. 19G, in one embodiment, the first leg 222A of thesurgical fastener 220 has a distal end 226A with the first insertion tip228A having the distal-most point 229A. In one embodiment, the firstinsertion tip 228A is skewed outwardly relative to the longitudinal axisA₁ of the first leg 222A. The first leg 222A includes the distal barb230A that extends inwardly toward the second leg 222B of the surgicalfastener 220. The second leg 222B has a distal end 226B with the secondinsertion tip 228B having the distal-most point 229B. In one embodiment,the second insertion tip 228B is skewed outwardly relative to thelongitudinal axis A₂ of the second leg 222B. The second leg 222Bincludes the distal barb 230B that extends inwardly toward the first leg222A. In one embodiment, the distal barbs 230A, 230B extend toward oneanother, oppose one another, and are aligned with one another adjacentthe distal ends 226A, 226B of the respective first and second legs 222A,222B. The central axis A₃ bisects the surgical fastener into a firsthalf including the first leg 222A and a second half including the secondleg 222B.

Referring to FIGS. 19D and 19G, in one embodiment, the first distal barb230A and the first proximal barb 232A have respective thicknesses thatare less than the thickness or diameter of the first leg 222A, and thesecond distal barb 230B and the second proximal barb 232B haverespective thicknesses that are less than the thickness or diameter ofthe second leg 222B

Referring to FIGS. 19G and 19H, in one embodiment, the surgical fastener220 desirably includes a first major surface 250 that extends over a topside of the surgical fastener 220 and a second major surface 252 thatextends over an underside of the surgical fastener 220. In oneembodiment, the first major surface 250 is flat and extends over thecenter section 244 of the crown 242 and the first and second legs 222A,222B of the surgical fastener. In one embodiment, the second majorsurface 252 is also flat and extends over opposite sides of the centersection 244 of the crown 242 and the first and second legs 222A, 222B.The flat, first and second major surfaces 250, 252 may be used tocontrol the orientation of the surgical fastener as it moves distallythrough the shaft of an applicator instrument.

In one embodiment, the first leg 222A desirably has an outer surface227A that extends along the length of the first leg. In one embodiment,the outer surface 227A of the first leg 222A may include a flat surfacethat is used to control the orientation of the surgical fastener as itmoves distally through the shaft of an applicator instrument. In oneembodiment, the second leg 222B desirably has an outer surface 227B thatextends along the length of the second leg. In one embodiment, the outersurface 227B of the second leg 222B may include a flat surface that isused to control the orientation of the surgical fastener as it movesdistally thorough the shaft of an applicator instrument.

Referring to FIGS. 19H and 20, in one embodiment, the flat top andbottom major surfaces 250, 252 of the surgical fastener 220 enable aplurality of surgical fasteners to be stacked one atop another with theflat major surfaces of adjacent surgical fasteners engaging one anotherwithin the stack. FIG. 20 shows a stack of three surgical fasteners220A-220C. The bottom surgical fastener 220A in the stack has a flat topsurface 250A and a flat bottom surface 252A. The flat bottom surface252B of the second surgical fastener 220B in the stack is in contactwith the flat top surface 250A of the first surgical fastener 220A. Theflat bottom surface 252C of the third surgical fastener 220C in thestack is in contact with the flat top surface 250B of the secondsurgical fastener 220C. As shown in FIG. 20, the flat major surfaces ofthe respective surgical fasteners are in contact with one another formaintaining the respective surgical fasteners in the stacked array.Although FIG. 20 shows three stacked surgical fasteners 220A-2200, inother embodiments, the number of surgical fasteners in a stack may befive, 10, 20, 30, or more. In one embodiment, the surgical fasteners maybe loaded into a cartridge 116 (FIG. 2A) to form a stack of deployablesurgical fasteners.

Referring to FIGS. 21A-21D, in one embodiment, an insertion tool 260 isused for advancing surgical fasteners toward a distal end of anapplicator instrument. In one embodiment, the insertion tool 260preferably includes a proximal end 262 that may be coupled with a distalend of a flexible member 160 and a distal end 264 that is adapted toengage the proximal end of a surgical fastener. In one embodiment, theinsertion tool 260 and the flexible member 160 are features on the samepart.

Referring to FIGS. 19A, 19E, and 21A-21D, in one embodiment, theinsertion tool 260 preferably includes opposing C-shaped projections266A, 266B that oppose one another at the distal-most end of theinsertion tool. In one embodiment, the C-shaped projections are designedto engage the C-shaped surfaces 240A, 240B of the bridge at the proximalend of the surgical fastener 220. In one embodiment, the insertion tool260 includes a surface 268, such as a flat surface, adjacent the distalend of the insertion tool that is surrounded by the opposing C-shapedprojections 266A, 266B. In one embodiment, the crown 242 at the proximalend of the surgical fastener is disposed within the space bounded by theC-shaped projections 266A, 266B. The distal surface 268 may or may notengage the center section 244 and the first and second laterallyextending flanges 246A, 246B of the crown at the proximal end of asurgical fastener. In one embodiment, the center section 244 andlaterally extending flanges 246A, 246B of the insertion control surface242 has a height H₁ (FIG. 19C) and the C-shaped projections 266A, 266Bhave a height H₂ (measured from surface 68) that is greater than theheight H₁ so that the distal surface 268 is spaced from the crown 242when the C-shaped projections 266A, 266B engage the flat surfaces 240A,240B. As a result, all of the insertion force transferred from theinsertion tool 260 to the surgical fastener 220 is transferred via theC-shaped projections 266A, 266B of the insertion tool engaging theC-shaped surfaces 240A, 240B aligned with the proximal ends of therespective first and second legs 222A, 222B.

In one embodiment, the insertion tool 260 preferably includes a fin orstripper ramp 270 that extends above the C-shaped projections 66A, 66Bat the distal end thereof. The stripper ramp 270 has a distal face 272that lies in a plane with the distal faces 274A, 274B of the respectiveC-shaped projections 266A, 266B. In one embodiment, the insertion toolincludes an attachment flange 275 at the proximal end 262 thereof thatis coupled or attached with the distal end of a flexible member so thatthe insertion tool may move distally and proximally with the flexiblemember 160. The insertion tool may also be part of the flexible member.

In one embodiment, the insertion tool 260, coupled with the distal endof a flexible member 160 via the attachment flange 275, is advanceddistally toward the trailing end of a surgical fastener whereupon thedistal-most face 272 of the ramp 270 engages the crown 242 (FIG. 19B) atthe proximal/trailing end of the surgical fastener. As the insertiontool advances distally, the proximal end of the surgical fastener isdesirably directed into alignment with the major distal surface 268 atthe distal end 264 of the insertion tool 260 so that the center section244 and the first and second laterally extending flanges 246A, 246B(FIG. 19E) of the crown 242 are disposed between the opposing C-shapedprojections 266A, 266B of the insertion tool 260.

Referring to FIGS. 21A-21 D, in one embodiment, the insertion tool 260has a flat top surface 290, a flat bottom surface 292, a first flat sidesurface 294A, and a second flat side surface 294B. As will be describedin more detail herein, in one embodiment, the flat surfaces 290, 292,294A, and 294B are used to control the orientation of the insertion tool260 as it moves distally in an applicator instrument.

Referring to FIGS. 19E and 21D, in one embodiment, when the insertiontool engages the proximal end of the surgical fastener 220, the lateralside surfaces 246A, 246B of the center section 244 may engage the ends276 of the opposing C-shaped projections 266A, 266B for furthercontrolling the orientation of the surgical fastener as it is advanceddistally by the insertion tool 260.

Referring to FIGS. 19D and 22A-22D, in one embodiment, the insertiontool 260 may be advanced until the distal end 264 of the insertion toolcaptures the crown 242 (FIG. 19B) located at the proximal end of thesurgical fastener 220. In one embodiment, the center section 244 and thefirst and second laterally extending flanges 246A, 246B (FIG. 19B) ofthe crown 242 are captured between the first C-shaped projection 266Aand the second C-shaped projection 266B at the distal end 264 of theinsertion tool 260. The distal faces 274A, 274B of the C-shapedprojections 266A, 266B preferably abut against the C-shaped surfaces240A, 240B (FIG. 19E) provided at the proximal ends of the respectivefirst and second legs 222A, 222B. In one embodiment, the C-shapedprojections 266A, 266B have a height H₂ (FIG. 21C) that is greater than0.020 inches so that the major distal surface 268 of the insertion tool260 does not engage the crown 242 at the proximal end of the surgicalfastener. As a result, all of the insertion force that is transferredfrom the insertion tool 260 to the surgical fastener 220 is transmittedvia the C-shaped projections 266A, 266B engaging the C-shaped surfaces240A, 240B aligned with the proximal ends of the first and second legs222A, 222B.

Referring to FIGS. 22A-22D, in one embodiment, when the crown of thesurgical fastener 220 is engaged by the distal end of the insertion tool260, the flat top surface 290 of the insertion tool 260 is aligned withthe flat top surface 250 of the surgical fastener 220, the flat bottomsurface 292 of the insertion tool 260 is aligned with the flat bottomsurface 252 of the surgical fastener 220, the first flat side surface294A of the insertion tool 260 is aligned with the flat side surface227A of the first leg 222A of the surgical fastener 220, and the secondflat side surface 294B of the insertion tool 260 is aligned with theflat side surface 227B of the second leg 222B of the surgical fastener220.

Referring to FIG. 23, in one embodiment, an applicator instrument fordispensing surgical fasteners preferably has an elongated shaft 102(FIG. 1A) with an elongated conduit 300 for guiding a surgical fastenerand an insertion tool joined with the surgical fastener toward thedistal end of the elongated shaft. In one embodiment, the elongatedconduit 300 preferably includes a top wall 302, a bottom wall 304, andside walls 306A, 306B that extend between the top wall and the bottomwall. The top wall 302 of the elongated conduit 300 has an elongated topnotch 308 formed therein and the bottom wall 304 has an elongated bottomnotch 310 formed therein. In one embodiment, the elongated top andbottom notches 308, 310 oppose one another and are in alignment with oneanother.

Referring to FIG. 24, in one embodiment, the distal end of the insertiontool 260 engages the proximal end of the surgical fastener 220 foradvancing/pushing the surgical fastener toward the distal end of theelongated shaft of the applicator instrument. In one embodiment, theflat top surface 250 of the surgical fastener 220 and the flat topsurface 290 (FIG. 21A) of the insertion tool 260 are opposed by the topwall 302 of the elongated conduit 300, and the flat bottom surface 252of the surgical fastener 220 and the flat bottom surface 292 (FIG. 21A)of the insertion tool 260 are opposed by the bottom wall 304 of theelongated conduit 300. In addition, the flat side surface 227A of thefirst leg 222A of the surgical fastener 220 and the first flat sidesurface 294A (FIG. 22C) of the insertion tool 260 are opposed by thefirst side wall 306A of the elongated conduit 300, and the flat sidesurface 227B of the second leg 222B of the surgical fastener 220 and thesecond flat side surface 294B (FIG. 22D) of the insertion tool 260 areopposed by the second side wall 306B of the elongated conduit 300. Theopposing top wall 302, bottom wall 304, and side walls 306A, 306Bpreferably guide and control the orientation of the surgical fastener220 and the insertion tool 260 as the joined elements are drivendistally through the elongated conduit 300.

In one embodiment, as the insertion tool 260 moves distally through theelongated conduit 300, the stripper ramp 270 slides through theelongated top notch 308 in the top wall 302 of the elongated conduit 300and the attachment flange 275 slides through the elongated bottom notch310 in the bottom wall 304 of the elongated conduit 300. Theregistration of the stripper ramp 270 with the elongated top notch 308and the attachment flange 275 with the elongated bottom notch 310preferably provides further control over the orientation and stabilityof the surgical fastener 220 and insertion tool 260 as the joinedelements move distally through the elongated conduit 300.

Referring to FIG. 25A, in one embodiment, an applicator instrument fordispensing surgical fasteners preferably includes a cartridge system 316that utilizes a single linear path to strip a surgical fastener from thebottom of a surgical fastener stack and place the stripped surgicalfastener into alignment with a distal end of a flexible member fordispensing the surgical fastener from the distal end of an elongatedshaft. In one embodiment, prior to commencing a firing cycle, a surgicalfastener stack 378 is arrayed within the cartridge 316. A pusher 386 islocated distal to the surgical fastener stack 378. In one embodiment, anelevator 388 is aligned with a lower end of the cartridge 316. Thecartridge system includes a slide 390 that is in a proximal-mostposition. Referring to FIG. 25B, in one embodiment, when a user squeezesthe trigger of the applicator instrument, the slide 390 moves the pusher386 proximally for pushing the lower-most surgical fastener 376 out ofthe cartridge 316 and into the elevator 388.

Referring to FIG. 25C, as the user finishes squeezing the trigger, thepusher 386 stops moving proximally once the lower-most surgical fastener376 is fully inside the elevator 388. The elevator 388 moves down sothat the surgical fastener 376 is aligned with the distal end of theflexible member 360. During this stage, the slide 390 moves proximallyfrom the position shown in FIG. 25B.

Referring to FIG. 25D, when the applicator instrument fires, the slide390 has moved all the way to the left and the elevator 388 is all theway down. The flexible member 360 moves along the lower guide 396 foradvancing the surgical fastener 376 toward the distal end of theelongated shaft.

Referring to FIGS. 26A-26B, 26B-1, and 26C, in one embodiment, anapplicator instrument includes a cartridge system 416 and a firingsystem that has one path to strip a surgical fastener from a bottom of asurgical fastener stack during the insertion motion and a different pathto follow on the retraction of the flexible member 460. Referring toFIG. 26B-1, in one embodiment, the cartridge system and the firingsystem utilize a racetrack arrangement 465 for providing the first pathfor distal movement of the flexible member 460 and the second path onthe return, proximal motion of the flexible member. In one embodiment,the leading end 460A of the flexible member 460 is wider to engage withthe upper path and a thinner section 460B of the flexible member 460just proximal to the leading end 460A is thinner to allow the flexiblemember to pass between the first and second paths of the racetrackarrangement 465.

Referring to FIGS. 27A-27C, in one embodiment, an applicator instrumentutilizes a cartridge system 516 having a rotary motion member 525 tostrip a surgical fastener and place the stripped surgical fastener intoproper alignment with a distal end of a flexible member 560 foradvancement toward the distal end of an elongated shaft. Providing acartridge system 516 with rotary motion member 525 enables tissuefasteners to be stacked in the cartridge in any orientation relative tothe motion of the flexible member 560. The rotary motion memberpreferably rotates the surgical fasteners 576 through any anglenecessary to bring the surgical fasteners in line with the distal end ofthe flexible member 560 (90 degree rotation for example).

Referring to FIGS. 28A and 28B, in one embodiment, the cartridge system616 includes a rotary drum 625 containing a plurality of surgicalfasteners 676. The cartridge 616 may be side loading for mounting ontothe side of a housing 608 of an applicator instrument 600. In oneembodiment, a distal end of a flexible member 660 passes through anopening in the rotary drum 625 that contains a surgical fastener 676 foradvancing the surgical fastener toward a distal end of an elongatedshaft. In one embodiment, movement of the trigger rotates the cartridge616 to present the next surgical fastener for insertion.

Referring to FIGS. 29A and 29B, in one embodiment, a cartridge 716 witha rotatory drum may be top mounted onto the housing 708 of an applicatorinstrument 700. The distal end of a flexible member 760 advances throughthe rotatory drum 725 for engaging a surgical fastener 776 for beingdispensed from a distal end of an elongated shaft 702. In oneembodiment, movement of the trigger rotates the cartridge 716 to presentthe next surgical fastener for insertion

Referring to FIGS. 30A and 30B, in one embodiment, an applicatorinstrument 800 having one or more of the features disclosed hereinincludes an elongated shaft 802 having an articulating distal end 806.The applicator instrument 800 includes a housing 808 and a handle 810coupled with the housing. The handle 810 may be reconfigured between thepistol configuration shown in FIG. 30A and the in-line configurationshown in FIG. 30B, as described in detail herein. The applicatorinstrument 800 preferably includes an articulation lever 814 provided onthe housing 808 that may be moved between a horizontal configuration forstraightening the distal end 806 of the elongated shaft 802 and avertical orientation for articulating the distal end 806 of theelongated shaft 802. The elongated shaft 802 may be articulated with theapplicator instrument in either the pistol grip configuration of FIG.30A, the in-line configuration of FIG. 30B, or numerous positionstherebetween.

Referring to FIG. 31A, in one embodiment, the applicator instrument 800preferably includes a housing 808 and an elongated shaft 802 projectingfrom a distal end of the housing 808. In one embodiment, the applicatorinstrument 800 includes an upper articulation band 805A and a lowerarticulation band 805B that are coupled with an articulating member 815(FIG. 31B) located at the distal end 806 of the elongated shaft 802.

The articulation system preferably includes an upper slider 820A that ispositioned over the top of the elongated shaft 802 and a lower slider820B that is positioned below the elongated shaft. The upper slider 820Ais attached to the proximal end of the upper articulation band 805A andthe lower slider 820B is attached to the proximal end of the lowerarticulation band 805B. The articulation system includes a yoke 822 thatis coupled with the upper and lower sliders 820A, 820B. In oneembodiment, the yoke 822 is capable of rotating relative to thelongitudinal axis of the elongated shaft 802. An upper tensionadjustment screw 825A preferably connects the upper slider 820A with anupper end of the yoke 822 and a lower tension adjustment screw 825Bpreferably connects the lower slider 820B with a lower end of therotatable yoke 822.

In one embodiment, the articulation system includes a cam plate 830 thatis rotated by the articulation lever 814 (FIG. 30B) for moving the camplate between a horizontal configuration associated with a straightelongated shaft and a vertical orientation associated with a fullyarticulated elongated shaft. The articulation system includes anover-center assembly 835 coupled with the distal end of the cam plate830 for forcing the cam plate 830 into one of two positions, namely, thehorizontal configuration associated with a straight elongated shaft anda vertical orientation associated with a fully articulated elongatedshaft. If the cam plate 830 is at an intermediate position between ahorizontal orientation and a vertical orientation, the over-centerassembly 835 desirably forces the cam plate 830 to rotate into eitherthe horizontal orientation or the vertical orientation. The mechanism toprovide this force is a compression spring constrained between twostruts. The upper strut is pivotally attached to the housing 808 and thelower strut is pivotally attached to the cam plate 830. Rotating the camplate 830 changes the force installed in the compression spring.

Referring to FIGS. 31A and 31B, in one embodiment, the upper and lowerarticulation bands 805A, 805B extend to the articulation member 815 atthe distal end 806 of the elongated shaft 802. In one embodiment, thearticulation member 815 includes a plurality of articulating segments orlinks that are coupled together at the distal end 806 of the elongatedshaft 802, and that are adapted to pivot relative to one another. In oneembodiment, the articulating member 815 includes a proximal articulationsegment 840 attached to a distal end of the elongated shaft 802, aplurality of intermediate articulating segments 842A-842D, and a distalarticulating segment 844 that extends to a distal-most end 806 of theelongated shaft 802. In one embodiment, a distal end face of the distalarticulating segment 844 preferably has castling 846 or projectionsformed thereon for engaging an opposing surface such as a surgical meshpositioned over tissue. The distal-most end of the distal articulatingsegment 844 has an opening 848 for dispensing a surgical fastenerthrough the opening. The upper and lower articulating bands 805A, 805Bdesirably pass through the elongated shaft 802, the proximalarticulating segment 840, and the intermediate articulating segments842A-842D for being affixed to respective upper and lower portions ofthe distal articulating segment 844.

Referring to FIGS. 32A and 32B, in one embodiment, when the articulationlever 814 (FIGS. 30A and 30B) is moved into the vertical orientation,the cam plate 830 rotates in a counterclockwise direction whereupon itis urged by the over-center system 835 to remain in the verticalorientation. The rotation of the cam plate 830, in turn, causesclockwise rotation of the yoke 822, which causes the upper slider 820Ato move proximally and the lower slider 820B to move distally. As thesliders 820A, 820B move, tension is increased in the upper articulationband 805A while enabling the lower articulation band 805B to movedistally. As a result of increasing the tension on the upperarticulation band 805A while enabling lower articulation band 805B tomove distally, the distal articulating segment 844 moves into thearticulated configuration shown in FIG. 32B. For example, a minimumdifferential band tension is needed to provide a resistance to 2.0-2.5lbs applied radially to the distal end 806 of the elongated shaft 802.This amount of resistance ensures that the distal end of the instrumentis sufficiently stiff to accommodate the needs of hernia repairprocedures, including mesh manipulation and firing of the applicator.

Referring to FIGS. 33A-33C, in one embodiment, the articulation controllever 814 is in a horizontal configuration so that the cam plate 830 hasa horizontal orientation and the over-center spring 835 urges the camplate 830 to remain in the horizontal orientation. With the articulationcontrol lever 814 in the horizontal orientation, the upper slider 820Aand the lower slider 820B are in alignment with one another along thelength of the elongated shaft 802, and the rotatable yoke 822 has anupper end that is distal to a lower end thereof. With the articulationcontrol lever 814 in the horizontal orientation, the upper articulationband 805A experiences little or no tension compared to the lowerarticulation band 805B so that the articulation member 814 at the distalend 806 of the elongated shaft 802 is in a straight configuration.

Referring to FIGS. 34A-34C, in on embodiment, when the articulationcontrol lever 814 is rotated into a vertical orientation, the cam plate830 is also in a vertical orientation and the over-center spring 835urges the cam plate 830 to remain in the vertical orientation. As thecam plate rotates from the horizontal orientation (FIG. 33A) to thevertical orientation shown in FIG. 34A, the rotatable yoke 822 rotatesin a clockwise direction so that the upper end of the yoke 822 isproximal to the lower end of the yoke. As a result, the upper slider820A moves proximally for tensioning the upper articulation band and thelower slider 820B moves distally for providing little or no tension onthe lower articulation band, compared to the upper articulation band.Referring to FIG. 34E, the tension on the upper articulation bandarticulates the articulation assembly 815 at the distal end 806 of theelongated shaft 802.

Referring to FIG. 35, in one embodiment, an intermediate articulatingsegment 842 preferably has a proximal end 850 and a distal end 852. Theintermediate articulating segment 842 desirably has an upper channel 854adapted to enable the upper articulating band 805A (FIG. 31A) to passtherethrough and a lower channel 856 adapted to enable the lowerarticulation band 805B (FIG. 31A) to pass therethrough. The intermediatearticulating segment 842 also desirably includes a central passageway858 through which a surgical fastener and the distal end of the flexiblemember 160 may pass for pushing a surgical fastener toward the distalend of the elongated shaft.

In one embodiment, each lateral side of the intermediate articulatingmember 842 has a cylindrical pocket 860 that enables adjacentarticulating segments to mesh with and pivot relative to one another. Inone embodiment, the cylindrical pocket 860 includes upper and lowerwings 862A, 862B that control the pivoting range of an adjacentarticulating member.

In one embodiment, the proximal end of the intermediate articulatingsegment 842 has a cylindrical shaped projection 864 with a T-shaped head865 that is adapted to be seated within the cylindrical pocket 860 of anadjacent articulating segment. When the projection 864 is inserted intoa pocket 860 of an adjacent segment, the T-shaped head 865 is seated ina concave gap 861 of the pocket 860 and the wings 862A, 862B limit thepivoting movement of the adjacent articulating segments relative to oneanother.

FIG. 32B shows how the projection 864 of a distal segment fits withinthe cylindrical pocket 860 of a proximal segment whereupon the segmentsmay pivot relative to one another, with the degree of pivotingcontrolled by the upper and lower wings 862A, 862B. Additionally, theT-shaped head on the projection 864 engages with the wings to preventthe segments from separating from each other, especially when externalstresses are applied to the distal end of the elongated shaft.

Referring to FIG. 36, in one embodiment, an applicator instrumentincludes an elongated shaft 902 with a conduit 905 extendingtherethrough that is adapted to receive a flexible member 960 as theflexible member moves toward the distal end of the elongated shaft 902for dispensing a surgical fastener. In one embodiment, the height of theconduit 905 is greater than the thickness of the flexible member 960 sothat the flexible member 960 may buckle a controlled amount to act as adamper and/or limit the travel of the flexible member. In oneembodiment, the taller sections of the conduit 905 relative to thethickness of the flexible member 960 may be contained within adesignated or limited area of the elongated shaft 902 for providing thedampening effect.

Referring to FIG. 37, in one embodiment, a distal end 1006 of anelongated shaft 1002 includes a distal positive stop 1015 that extendsinto the elongated conduit of the elongated shaft 1002. In oneembodiment, an insertion tool 1074 attached to a distal end of theflexible member 1060 preferably includes a rear attachment flange 1025that is adapted to contact the distal positive stop 1015 for haltingfurther distal movement of the insertion tool 1074 and the flexiblemember 1060.

Referring to FIG. 38, in one embodiment, an applicator instrument 1100has one or more of the structural components described herein andpreferably includes first and second sliders 1120A, 1120B coupled with ayoke 1122 for adjusting the tension on articulation bands. A tensioningspring 1185 is coupled with the second slider 1120B. In one embodiment,the tensioning spring 1185 desirably provides tension force relief inthe event that excessive tension force is applied to the lowerarticulation band secured to the articulation member at the distal endof the elongated shaft 1102.

Referring to FIG. 39, in one embodiment, an applicator instrument 1200has one or more of the structural components described herein andpreferably includes first and second sliders 1220A, 1220B coupled with ayoke 1222 for adjusting the tension on upper and lower articulationbands. A first tensioning spring 1285A is coupled with the first slider1220AB. In one embodiment, the first tensioning spring 1285A desirablyprovides tension force relief in the event that excessive tension forceis applied to the upper articulation band secured to the articulationmember located at the distal end of the elongated shaft 1202. In oneembodiment, the second tensioning spring 1285B desirably providestension force relief in the event that excessive tension force isapplied to the lower articulation band secured to the articulationmember at the distal end of the elongated shaft 1202.

Referring to FIG. 40, in one embodiment, a drive train 124 for anapplicator instrument may include a trigger gear 113 attached to thetrigger 112, a drive gear 177 that meshes with the trigger gear 113, aclutch gear 179 that meshes with the drive gear 177, a mid gear 181 thatmay be coupled with the clutch gear 179, a one-way bearing 183, and aclutch gear shaft 193 coupled with the clutch gear 179 forsimultaneously rotating with the clutch gear. In one embodiment, theone-way bearing 183 is disposed on the clutch gear shaft 193. In oneembodiment, the gears preferably have teeth for meshing with other gearsof the gear train 124.

Referring to FIGS. 40 and 41A, in one embodiment, the drive train for anapplicator instrument preferably includes the drive gear 177 havingteeth that mesh with teeth on the clutch gear 179. When the trigger isfully extended in the ready to fire position, the drive gear 177 and theclutch gear 179 are disengaged via an interruption in the teeth patternon the drive gear 177. The drive train desirably includes the mid gear181 having a central opening that receives the one-way bearing 183,which, in turn, is mounted on the clutch gear shaft 193.

Referring to FIGS. 40 and 41B, in one embodiment, as the trigger 112 issqueezed, the trigger gear 113 rotates the drive gear 177 in thecounterclockwise direction shown in FIG. 41B. The teeth on the drivegear 177 engage the teeth on the clutch gear 179 for rotating the clutchgear 179 in the clockwise direction shown in FIG. 41B. As the clutchgear 179 rotates clockwise, the clutch gear shaft 193 drives the one-waybearing 183 in a clockwise direction during which the one-way bearing183 engages the mid gear 181 for rotating the mid gear in the clockwisedirection shown in FIG. 41B. In turn, the mid gear 181 drives thestorage reel 126 (FIG. 14A-1) to wind up the flexible member 160 on thestorage reel and store energy in the constant torque spring 172 (FIG.10B). In one embodiment, the one-way bearing 183 only engages and drivesrotation of the mid gear 181 when the clutch gear shaft 193 rotates inthe clockwise direction shown in FIG. 41B. The one-way bearing 183preferably free wheels when the clutch gear shaft 193 rotates in acounterclockwise direction that is opposite the clockwise direction sothat the clutch gear 179 and the mid gear 181 are decoupled from oneanother.

Referring to FIGS. 40 and 41C, when the trigger 112 is almost fullysqueezed (i.e., at the end of a trigger stroke), the interrupted toothsection 195 on the drive gear 177 results in the drive gear disengagingfrom the clutch gear 179. This disengagement allows the mid gear 181 andthe clutch gear 179 to move freely without any resistance from thetrigger 112 and the gear train. At this stage, the energy that is storedin the constant torque spring 172 (FIG. 10B) is released for driving thedrive wheel 128 (FIG. 16A) for advancing the flexible member 160 (FIG.16B) toward the distal end of the elongated shaft.

Referring to FIGS. 40 and 41D, in one embodiment, after the trigger hasbeen fully squeezed and the trigger return spring returns the triggerback to an open position, the trigger gear 113 rotates the drive gear177 in a clockwise direction. In turn, the drive gear 177 rotates theclutch gear 179 in a counterclockwise direction. As the clutch gear 179and the clutch gear shaft 193 rotate in the counterclockwise direction,the one-way bearing 183 will disengage from the clutch gear shaft 193.Thus, the counterclockwise rotation of the clutch gear 179 will not beconveyed to the mid gear 181, and therefore, the distal end of thefiring system that includes the drive wheel 128 and the storage reel 126will not be impacted by the trigger returning back to the open position.Thus, in one embodiment, the one-way bearing 183 disengages from theclutch gear shaft 193 when the clutch gear shaft rotates in acounterclockwise direction, whereupon the mid gear 181 will not berotated by the one-way bearing 183.

Referring to FIGS. 42A-42E, in one embodiment, the drive wheel 128, thestorage reel 126, and the spool 139 (FIG. 10B) are assembled onto acarriage 165. In one embodiment, the carriage 165 is normally springloaded distal but is held proximal by a catch 167. When the insertiontool 174 retracts, it releases the catch 167 and allows the carriage 165to move distal, urged by a spring. When the carriage 165 moves distal,the storage reel 126 disconnects from the drive train 124 and theconstant torque spring 172 accelerates the flexible member 160 and thesurgical fastener toward the distal end of the elongated shaft 102 forbeing inserted into tissue. Once delivered, the flexible memberexperiences compressive loads due to the inertia of the drive wheel 128.The reaction force to these compressive loads generates a torque on thedrive wheel 128, which allows the carriage 165 to move proximal andreset the catch 167. In one embodiment, inserting the cartridge 116 intothe housing pushes the carriage 165 toward the proximal end of thehousing, which engages/meshes the storage reel 126 with the drive train124 so that the applicator instrument may be fired. In one embodiment,the cartridge 116 also engages the catch 167. Removing the cartridge 116releases the catch 167 and allows the carriage 165 to move distal,disengaging the drive gear 165 and the storage reel 126 and preventingthe device from being fired.

Referring to FIG. 42A, in one embodiment, the drive wheel 128, storagereel 126, and spool 139 (FIGS. 10A and 10B) are assembled onto acarriage 165. The carriage 165 is spring loaded distal but is heldproximal by a catch 167.

Referring to FIGS. 42B and 42C, in one embodiment, when the insertiontool 174 fully retracts, it releases the catch 167 and allows thecarriage 165 to move distal, urged by the spring.

Referring to FIGS. 42C and 42D, in one embodiment, when the carriage 165moves distal, the storage reel 126 disconnects from the drive train 124and the constant torque spring 172 accelerates the flexible member 160and the surgical fastener toward the distal end of the elongated shaft102 for being inserted into tissue.

Referring to FIG. 42E, in one embodiment, once delivered, the flexiblemember 160 experiences compressive loads due to the inertia of the drivewheel 128. The reaction force to these compressive loads generates atorque on the drive wheel 128, which allows the carriage 165 to moveproximal and reset the catch 167.

In one embodiment, the drive wheel 128, storage reel 126, and spool areassembled onto a carriage. The carriage is spring loaded distal but isheld proximal by a catch. When the insertion tool 174 retracts, itreleases the catch and allows the carriage 165 to move distal, urged bythe spring. When the carriage 165 moves distal, the storage reel 126disconnects from the drive train 124 and the constant torque spring 172(FIGS. 10A and 10B) accelerates the flexible member 160 and the surgicalfastener toward the distal end of the elongated shaft 102 for beinginserted into tissue. Once delivered, the flexible member experiencescompressive loads due to the inertia of the drive wheel 128. Thereaction force to these compressive loads generates a torque on thedrive wheel 128, which allows the carriage to move proximal and resetthe catch. As a refinement to the above, adding the cartridge 116 pushesthe carriage 165 proximal engaging the drive train and storage reel intomesh (allowing the device to be fired). The cartridge 116 also engagesthe latch 167. Removing the cartridge 116 releases the latch 167 andallows the carriage 165 to move distal, disengaging the mid gear andtape gear and preventing the device from being fired.

In one embodiment, the applicator instrument may only be fired when thecartridge 116 is inserted into the applicator instrument and cannot befired when the cartridge 116 has been removed from the applicatorinstrument. Referring to FIGS. 43A-43C, in one embodiment, inserting thecartridge 116 into the applicator instrument pushes the carriage 165toward the proximal end of the applicator instrument (to the right inFIGS. 43A-43C), which, in turn, couples and/or meshes the drive train124 with the storage reel 126 (FIGS. 43B and 43C) for enabling theapplicator instrument to be fired. In one embodiment, the cartridge 116may also engage the catch 167. Referring to FIG. 43C, once the cartridgeis in place, the cartridge no longer interacts with the carriage. In oneembodiment, the cartridge 116 has a notch 159 formed on the right sideof the cartridge, which allows the carriage 165 to translate proximallyand distally, as necessary, during each firing stroke.

In one embodiment, removing the cartridge 116 releases the catch 167 forallowing the carriage 165 to move distal (to the left in FIGS. 43A-43C),thereby disengaging the drive train 124 from the storage reel 126 andpreventing the applicator instrument from being fired.

Referring to FIG. 44A, in one embodiment, a firing system includes aflexible member 1360 that is initially retracted and held proximal by apower spring 1375. A friction drive wheel 1328 has potential energystored therein. In one embodiment, the energy is stored via a constanttorque spring 1372 pre-wound onto the drive wheel during assembly, suchthat the spring has adequate length to facilitate multiple cycles.Alternative stored energy means may include electro-mechanical,pneumatic, mechanical, motor driven, compressed gas, or other well-knownenergy sources. The friction drive wheel 1328 is held in place by alever lock 1370, preventing clockwise rotation.

Referring to FIG. 44B, in one embodiment, squeezing a trigger of theapplicator instrument engages an idler wheel 1375 with the flexiblemember 1360 and toggles the level lock 1370. At this stage, the constanttorque spring 1372 has more force than the power spring 1375, and drivesthe flexible member 1360 distally (to the left in FIG. 44B).

Referring to FIG. 44C, in one embodiment, a proximal or trailing end ofthe flexible member 1360 includes a wedge 1361 that allows the springloaded lever 1370 to re-engage with the friction drive wheel 1328. Atthis stage, the idler wheel 1375 separates from the flexible member1360, which enables the power spring 1375 to retract the flexible member1360.

In one embodiment, some of the energy stored in the constant torquespring 1372 is used on each firing cycle. In one embodiment, theconstant torque spring 1372 is sufficiently long to provide enoughenergy for many firing cycles. This design has many benefits includingthat the force required of the user is very low (e.g., a user may onlyneed to engage the idler wheel 1375 and release the lever lock 1370).

In an alternate embodiment, the constant torque spring is pre-wound ontothe drive wheel during assembly to have sufficient stroke for multiplecycles. A latch holds the drive wheel in place, preventing rotation.During the trigger squeeze, the flexible member is wound onto thestorage reel but is disengaged from the drive wheel, reducing thetrigger force for the user. When the user has nearly completed thetrigger stroke, the trigger releases a latch, which engages an idlerwith the flexible member and the drive wheel. The latch also releasesthe constraint preventing rotation on the drive wheel. This allows thedrive wheel to accelerate due to the force applied by the constanttorque spring. The flexible member extends distally, delivering thefastener. As the flexible member reaches the end of its travel, afeature on the flexible member resets the latch and disengages theflexible member from the drive wheel.

Referring to FIGS. 44A-44C, in one embodiment, the constant torquespring 1372 is pre-wound onto the drive wheel during assembly to havesufficient stroke for multiple cycles. A latch holds the drive wheel inplace, preventing rotation. During the trigger squeeze, the flexiblemember is wound onto the storage reel but is disengaged from the drivewheel, reducing the trigger force for the user. When the user has nearlycompleted the trigger stroke, the trigger releases a latch, whichengages the flexible member with the drive wheel and releases theconstraint preventing rotation on the drive wheel. This allows the drivewheel to accelerate due to the force applied by the constant torquespring. The flexible member extends distally, delivering the fastener.As the flexible member reaches the end of its travel, a feature on theflexible member resets the latch and disengages the flexible member fromthe drive wheel.

FIG. 45A shows an applicator instrument 1400 having one or more of theelements described herein. In FIG. 45A, the applicator instrument 1400has a flexible member 1460 in an extended position for dispensing asurgical fastener. In FIG. 45B, the flexible member 1460 is in aretracted position. In one embodiment, a torsion spring is assembledwith the storage reel 1426. The torsion spring is preferablypre-assembled with a torque greater than that required to wind theflexible member 1460 onto the storage reel. When the insertion tool 1474is fully retracted, it preferably engages a proximal stop 1473 thatprevents further proximal travel of the insertion tool 1474. At thispoint, the flexible member 1460 is stationary and further travel of thetrigger 1412 and gear train 1424 only results in extra compression ofthe torsion spring. Such a system accounts for tolerances and ensuresthat the insertion tool 1474 is reliably retracted proximal of thecartridge 116 (FIG. 13B) on every firing cycle.

Referring to FIG. 46A, in one embodiment, an applicator instrument 1500for dispensing surgical fasteners includes a firing system thatincorporates the “coiled snake” concept. In one embodiment, theapplicator instrument 1500 includes an actuator or trigger 1512 that iscoupled with a gear train 1524, a torsion spring 1572, a pair of drivewheels 1528A and 1528B, and a flexible member 1560 that is advanceddistally by the drive wheels.

Referring to FIG. 46B, in one embodiment, as the user squeezes thetrigger 1512, one end of the torsion spring is held in place by a latch1515 and the other end is rotated, compressing the torsion spring andstoring potential energy. Referring to FIG. 46C, near the conclusion ofthe trigger compression stroke, a latch 1515 releases the energy thathas been previously stored in the torsion spring 1572. In turn, theenergy from the torsion spring 1572 drives the gear train 1524.Referring to FIG. 46D, in one embodiment, the stored energy istransmitted through the gear train 1524 for rotating the upper drivewheel 1528A in a clockwise direction and the lower drive wheel 1528B ina counterclockwise direction. Referring to FIG. 46E, in one embodiment,the rotating drive wheels 1528A and 1528B, which may be friction wheelsor cogged wheels, drive the flexible member 1560 toward a distal end ofa cannula for delivering a surgical fastener from the distal end of thecannula.

In one embodiment, an applicator instrument for dispensing surgicalfasteners may have a firing system that incorporates the “coiled snake”concept disclosed herein whereby the firing system uses energy stored ina spring that is located distal to the gear train. In one embodiment, anapplicator instrument for dispensing surgical fasteners may have afiring system that incorporates the “coiled snake” concept disclosedherein whereby the firing system uses energy stored in a spring locatedprior or proximal to the gear train, with the energy being releasedthrough the drive train to drive the flexible member. In one embodiment,a user squeezes a trigger, handle and/or actuator for compressing atorsion spring. At the conclusion of the compression stroke, a latch isdisengaged for releasing the energy stored in the torsion spring. In oneembodiment, the energy stored in the compression spring is transmittedthrough a gear train to a set of drive wheels. The released energyrotates the drive wheels, which, in turn, drive the flexible member downa cannula to deliver the surgical fastener from the distal end of thecannula.

In one embodiment, the applicator instruments disclosed herein may beused during surgical procedures such as hernia repair procedures. In oneembodiment, the patient is prepared for surgery in administeringanesthesia. Abdominal access is prepared by inserting two or more portsthrough the abdominal wall and insufflating the abdominal cavity. Thehernia site is assessed under direct visualization using a laparoscopiccamera. Adhesions are reduced and the peritoneum sac is excised ifappropriate. A mesh is placed into the abdominal cavity. The surgeonselects from a variety of cartridges to identify one appropriate for thetype of hernia repair being performed. The variety may include differentfastener designs, materials, or quantities. The cartridge is attached tothe applicator instrument. The distal end of an elongated shaft isadvanced through one of the port openings. During a surgical procedure,the distal end of the elongated shaft may be articulated if necessary toaccess areas requiring fixation, such as the ipsilateral side of themesh, nearest the port. When the elongated shaft is passed through aport, the reconfigurable handle may be pivoted into a variety ofconfigurations to improve the ergonomics and maneuverability of thesurgeon, depending on the location of the target fixation site relativeto the port. The applicator instrument may be used to dispense surgicalfasteners for securing surgical mesh to tissue. Cartridges can bechanged for reloading or changing the type of surgical fastener beingdispensed by the applicator instrument. The articulated distal end isstraightened before removing the device through the port.

In one embodiment, the applicator instruments disclosed herein may beused during robotic surgical procedures such as hernia repairprocedures. In one embodiment, the patient is prepared for surgery inadministering anesthesia. Abdominal access is prepared by inserting twoor more ports through the abdominal wall and insufflating the abdominalcavity. A surgical robot is attached to the pre-placed ports. The herniasite is assessed under direct visualization using a laparoscopic camera.Adhesions are reduced and the peritoneum sac is excised if appropriate.A mesh is placed into the abdominal cavity. The surgeon selects from avariety of cartridges to identify one appropriate for the type of herniarepair being performed. The variety may include different fastenerdesigns, materials, or quantities. The cartridge is attached to theapplicator instrument. The distal end of an elongated shaft is advancedthrough one of the port openings. The housing assembly is attached tothe arm of a surgical robot. During a surgical procedure, the distal endof the elongated shaft may be articulated if necessary to access areasrequiring fixation, such as the ipsilateral side of the mesh, nearestthe port. The applicator instrument may be used to dispense surgicalfasteners for securing surgical mesh to tissue. Cartridges can bechanged for reloading or changing the type of surgical fastener beingdispensed by the applicator instrument. The articulated distal end isstraightened before removing the device through the port.

In one embodiment, the applicator instruments and surgical toolsdisclosed herein may be coupled with and/or be in communication with arobotic surgical system, such as the systems and devices disclosed in US2014/0005662 to Shelton, the disclosure of which is hereby incorporatedby reference herein. In one embodiment, the robotic surgical system mayhave a sterile barrier located between the applicator instruments andsurgical tools and the robotic part of the robotic surgical system,whereby the applicator instruments and surgical tools are located in thesterile environment.

In one embodiment, a robotic surgical system may have a mastercontroller and control systems such as the systems and devices disclosedin U.S. Pat. No. 7,524,320, the disclosure of which is herebyincorporated by reference herein. The master controller may have controlelements (e.g., knobs, actuators) that are engaged by a surgeon andmanipulated in space while the surgeon views a surgical site through avideo monitor and/or stereo display. The master controller may includemanual input devices that move with multiple degrees of freedom. In oneembodiment, the master control has an actuator for actuating surgicaltools (e.g., dispensing a surgical fastener).

In one embodiment, the robotic surgical system may include a roboticcart that is configured to actuate a plurality of surgical tools and/orinstruments. Various robotic surgery systems and methods employingmaster controller and robotic cart arrangements are disclosed in U.S.Pat. No. 6,132,368, the disclosure of which is hereby incorporated byreference herein. In one embodiment, a robotic cart may include a basefrom which surgical tools are supported. In one embodiment, the surgicaltools may be supported by a series of manually articulatable linkages,generally referred to as set-up joints, and a robotic manipulator. Thesestructures may have protective covers extending over much of the roboticlinkage. The protective covers may be optional, and may be limited insize or entirely eliminated to minimize the inertia that is encounteredby servomotors used to manipulate such devices, to limit the volume ofmoving components so as to avoid collisions, and to limit the overallweight of the robotic cart. In one embodiment, the robotic cart may havedimensions suitable for transporting the cart between operating rooms.The robotic cart is preferably configured to pass through standardoperating room doors and onto standard hospital elevators. The roboticcart preferably has a weight and includes one or more wheels that allowthe cart to be easily moved and positioned adjacent an operating table.

Other embodiments may incorporate a wide variety of alternative roboticstructures, including those described in U.S. Pat. No. 5,878,193, thedisclosure of which is hereby incorporated by reference herein.Additionally, while the data communication between a robotic componentand the processor of the robotic surgical system is described withreference to communication between the surgical tool and the mastercontroller, similar communication may take place between circuitry of amanipulator, a set-up joint, an endoscope or other image capture device,or the like, and the processor of the robotic surgical system forcomponent compatibility verification, component-type identification,component calibration communication, and confirmation of coupling of thecomponent to the robotic surgical system.

In one embodiment, during a surgical procedure, a surgeon may inputcontrol commands to the master controller or a control unit of therobotic surgical system, which “robotically-generates” output motionsthat are ultimately transferred to the applicator instruments disclosedherein. As used herein, the terms “robotically-generates” or“robotically-generated” refer to motions that are created by poweringand controlling the motors of the robotic surgical system and otherpower driven components. These terms are distinguishable from the terms“manually-actuatable” or “manually generated” which refer to actionstaken by a surgeon that result in control motions that are generatedindependent from those motions that are generated by powering the motorsof the robotic surgical system.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, which is only limited by thescope of the claims that follow. For example, the present inventioncontemplates that any of the features shown in any of the embodimentsdescribed herein, or incorporated by reference herein, may beincorporated with any of the features shown in any of the otherembodiments described herein, or incorporated by reference herein, andstill fall within the scope of the present invention.

What is claimed is:
 1. An applicator instrument for dispensing surgical fasteners comprising: an elongated shaft having a proximal end and a distal end; a housing connected with said proximal end of said elongated shaft; a trigger; a gear train coupled with said trigger, wherein said trigger is squeezable for moving said gear train for commencing a firing cycle; a firing system disposed in said housing, wherein said firing system is coupled with said gear train during an energy storing stage of said firing cycle and decoupled from at least one gear of said gear train during an energy releasing stage of said firing cycle, said firing system comprising a storage reel, a spool, a drive wheel located adjacent to said storage reel and said spool, a constant torque spring having a proximal end connected to said spool and a distal end connected to said drive wheel, a flexible member in contact with said drive wheel, said flexible member having a proximal end connected to said storage reel and a length that is configured to be driven by said drive wheel toward said distal end of said elongated shaft, wherein during the energy storing stage of said firing cycle said gear train is coupled with said storage reel for rotating said storage reel in a counterclockwise direction, which, in turn, winds said flexible member onto said storage reel for retracting said flexible member, which, in turn, rotates said drive wheel in a counterclockwise direction, which, in turn, winds said constant torque spring from said spool onto said drive wheel for storing energy in said constant torque spring.
 2. The applicator instrument as claimed in claim 1, wherein at the commencement of said firing cycle said flexible member is fully extended so that a distal end of said flexible member is adjacent said distal end of said elongated shaft.
 3. The applicator instrument as claimed in claim 2, wherein at the end of said energy storing stage of said firing cycle said flexible member is wound onto said storage reel and said distal end of said flexible member is retracted into said housing.
 4. The applicator instrument as claimed in claim 3, further comprising a cartridge containing a plurality of stacked surgical fasteners inserted into said housing, wherein at the end of said energy storing stage of said firing cycle said distal end of said flexible member is proximal to said plurality of stacked fasteners.
 5. The applicator instrument as claimed in claim 3, wherein during the energy releasing stage of said firing cycle said at least one gear of said gear train is decoupled from said storage reel so that said storage reel and said spool are able to rotate freely relative to said at least one gear of said gear train whereupon said constant torque spring unwinds from said drive wheel and winds onto said spool for releasing the energy stored in said constant torque spring, which, in turn, rotates said storage reel in a clockwise direction to unwind said flexible member from said storage reel and rotates said drive wheel in a clockwise direction to drive said distal end of said unwound flexible member toward said distal end of said elongated shaft.
 6. The applicator instrument as claimed in claim 5, further comprising: an insertion tool secured to said distal end of said flexible member; a proximal hard stop located in said housing that contacts said insertion tool at the end of said energy storing stage of said firing cycle for stopping proximal movement of said flexible member; a distal hard stop located at said distal end of said elongated shaft that contacts said insertion tool at the end of said energy releasing stage of said firing cycle for stopping distal movement of said flexible member;
 7. The applicator instrument as claimed in claim 5, wherein said gear train comprises: a trigger gear connected to said trigger; a drive gear that meshes with said trigger gear; a clutch gear that meshes with said drive gear; a clutch gear shaft upon which said clutch gear is mounted, wherein said clutch gear and said clutch gear shaft rotate simultaneously with one another; a one-way bearing mounted on said clutch gear shaft; a mid gear connected to said one-way bearing, wherein said one-way bearing transmits torque to said mid gear when rotating in a first direction and freewheels relative to said mid gear when rotating in an opposite, second direction.
 8. The applicator instrument as claimed in claim 7, further comprising: a handle connected to said housing; said trigger being coupled with said handle; wherein during said energy storing stage squeezing said trigger moves said trigger gear for rotating said drive gear in a counterclockwise direction, which, in turn, rotates said clutch gear in a clockwise direction, which, in turn, rotates said clutch gear shaft in a clockwise direction, which, in turn, rotates said one-way bearing in a clockwise direction, which, in turn, rotates said mid gear in a clockwise direction, which, in turn, rotates said storage reel in a counterclockwise direction for winding said flexible member onto said storage reel and retracting said distal end of said flexible member into said housing.
 9. The applicator instrument as claimed in claim 8, wherein said drive gear has an outer perimeter with a first section having gear teeth and a second an interrupted tooth section having no gear teeth.
 10. The applicator instrument as claimed in claim 9, wherein during said energy storing stage of said firing cycle said gear teeth on said first section of said outer perimeter of said drive gear mesh with gear teeth on said clutch gear so that said drive gear and said clutch gear rotate simultaneously with one another, and wherein during said energy releasing stage said second interrupted tooth section of said outer perimeter of said drive gear opposes said gear teeth on said clutch gear so that said mid gear is not coupled with said drive gear and can freewheel relative to said drive gear.
 11. The applicator instrument as claimed in claim 10, wherein said one-way bearing transmits torque from said clutch gear shaft to said mid gear as said clutch gear shaft rotates in a clockwise direction and said one-way bearing freewheels relative to said clutch gear shaft as said clutch gear shaft rotates in a counterclockwise direction.
 12. The applicator instrument as claimed in claim 5, wherein said flexible member comprises openings spaced from one another along the length of said flexible member, and wherein said drive wheel has teeth that mesh with said openings of said flexible member so that said counterclockwise rotation of said drive wheel moves said flexible member in a proximal direction and clockwise rotation of said drive wheel moves said flexible member in a distal direction.
 13. The applicator instrument as claimed in claim 5, further comprising: a notch formed in an outer perimeter of said storage reel; a pivoting stop disposed in said housing adjacent said outer perimeter of said storage reel, wherein during said energy storing stage of said firing cycle said pivoting stop is moved away from the outer perimeter of said storage reel by said flexible member as said flexible member is wound onto said storage reel, and wherein at the end of said energy releasing stage of said firing cycle said pivoting stop moves into engagement with said notch at the outer perimeter of said storage reel after said flexible member has been unwound from said storage reel to prevent further clockwise rotation of said storage reel.
 14. An applicator instrument for dispensing surgical fasteners comprising: a housing; a cartridge containing a plurality of stacked surgical fasteners inserted into said housing; an elongated shaft extending from said housing for dispensing said stacked surgical fasteners from a distal end of said elongated shaft; an actuator coupled with said housing; a gear train coupled with said actuator; a firing system configured to be sequentially coupled with and decoupled from said gear train during a firing cycle, said firing system comprising a storage reel, a spool, a drive wheel located adjacent to said storage reel and said spool, a constant torque spring having a proximal end connected to said spool and a distal end connected to said drive wheel, a flexible member in contact with said drive wheel, said flexible member having a proximal end connected to said storage reel; wherein said actuator is engaged for moving said gear train to commence said firing cycle, said firing cycle including an energy storing stage during which said gear train is coupled with said storage reel for rotating said storage reel and said spool in a counterclockwise direction, which, in turn, winds said flexible member about said storage reel, which, in turn, rotates said drive wheel in a counterclockwise direction, which, in turn, winds said constant torque spring from said spool onto said drive wheel for storing energy in said constant torque spring.
 15. The applicator instrument as claimed in claim 14, wherein said firing cycle includes an energy releasing stage during which said storage reel and said spool are decoupled from at least one gear of said gear train whereupon said constant torque spring unwinds from said drive wheel and winds onto said spool for releasing the stored energy in said constant torque spring, which, in turn, rotates said storage reel in a clockwise direction to unwind said flexible member from said storage reel and rotates said drive wheel in a clockwise direction to drive a distal end of said flexible member toward said distal end of said elongated shaft.
 16. The applicator instrument as claimed in claim 15, wherein said gear train comprises: an actuator gear connected to said actuator; a drive gear that meshes with said actuator gear; a clutch gear that meshes with said drive gear; a clutch gear shaft upon which said clutch gear is mounted, wherein said clutch gear and said clutch gear shaft rotate simultaneously with one another; a one-way bearing disposed on said clutch gear shaft, wherein said clutch gear shaft transmits torque through said one-way bearing when rotating in a first direction and said one-way bearing free wheels relative to said clutch gear shaft when said clutch gear shaft rotates in an opposite, second direction; a mid gear connected to said one-way bearing for rotating simultaneously with said one way bearing, said mid gear having teeth that mesh with teeth on said storage reel.
 17. The applicator instrument as claimed in claim 16, wherein during said energy storing stage, engaging said actuator moves said actuator gear for rotating said drive gear in a counterclockwise direction, which, in turn, rotates said clutch gear, said clutch gear shaft, said one-way bearing, and said mid gear in a clockwise direction, which, in turn, rotates said storage reel in a counterclockwise direction for winding said flexible member onto said storage reel.
 18. The applicator instrument as claimed in claim 17, wherein said drive gear has an outer perimeter with a first section having gear teeth and a second interrupted tooth section having no gear teeth, and wherein during said energy storing stage of said firing cycle said gear teeth on said first section of said drive gear mesh with gear teeth on said clutch gear so that said drive gear and said clutch gear rotate simultaneously with one another, and wherein during said energy releasing stage of said firing cycle said second interrupted tooth section of said drive gear opposes said gear teeth on said clutch gear so that said clutch gear is not meshed with said drive gear.
 19. The applicator instrument as claimed in claim 15, wherein said flexible member comprises a length extending between said proximal and distal ends thereof and openings spaced from one another along the length of said flexible member, and wherein said drive wheel has teeth that mesh with said openings of said flexible member during proximal and distal movement of said flexible member.
 20. A method of dispensing surgical fasteners comprising: providing an applicator instrument including a housing, an elongated shaft extending from said housing, and an actuator coupled with said housing; inserting a cartridge containing a plurality of stacked surgical fasteners into said housing; disposing a flexible member in said housing with a distal end of said flexible member located adjacent a distal end of said elongated shaft; engaging said actuator for building up energy in a firing system and retracting said distal end of said flexible member from said distal end of said elongated shaft to a first location inside said housing whereupon said distal end of said flexible member is proximal to said plurality of stacked surgical fasteners; transferring said built up energy to said flexible member for driving said distal end of said flexible member from said first location inside said housing to said distal end of said elongated shaft, wherein as said distal end of said flexible member moves from said first location to said distal end of said elongated shaft said distal end of said flexible member strips a surgical fastener from a bottom said plurality of stacked surgical fasteners and dispenses said stripped surgical fastener from said distal end of said elongated shaft. 